Quadratic Equation Tests — Pick a Level and Start
Tap a level to see every test in it. Start at Level 1 as soon as you can read the sum and product of the roots straight off the coefficients, then move to Level 2 with the timer running — that is where two relations get chained inside one question, exactly as the real paper does it.
Level 1 SSC CGL Level Checking… View tests
One rule applied cleanly — read the sum or product off the coefficients, split the middle term, test the discriminant, use the factor theorem once, compare two coefficient ratios. The equation is already in standard form or one step away, and the answer is a line or two out. Attempt these without the clock while the relations are still settling.
Level 2 Above SSC CGL Level Checking… View tests
Harder than the paper, on purpose. Two relations chained, the question run backwards so a result is given and a coefficient is asked, or a simplification needed before any rule applies — a power ladder climbed in reverse, a common root that turns out to equal the parameter itself, a discriminant proved positive for every value of k. Clear these and Tier I reads easy.
Quadratic equation is the chapter where algebra stops being manipulation and starts being reading. Almost every question in it can be answered from two numbers — the sum of the roots and their product — and almost every mistake in it comes from finding the roots when they were never needed. A candidate who internalises that one habit answers most of the chapter in under forty seconds a question.
It is also unusually good value per hour. The sum-and-product relations reappear in the algebraic identity chapters, the discriminant reappears whenever a question asks whether something is possible, and the factorising practice pays out in simplification and in data-sufficiency style framings. These practice tests put twenty-five quadratic questions in front of you in one sitting, each with a full solution and the shortcut, in English or Hindi.
How Many Quadratic Equation Questions Are Asked in SSC CGL?
Counted directly it is a one-to-two question chapter in Tier I. Counted with the places its relations are reused, it sits under a noticeably larger share of the algebra block — which is why it repays study out of proportion to its own mark count.
| Where it appears | Typical count | What is asked |
|---|---|---|
| Tier I — Quantitative Aptitude | 1–2 | Nature of roots, sum and product, one value of a parameter |
| Tier II — Mathematical Abilities | 2–4 | Symmetric functions of the roots, common roots, transformed equations |
| Inside the algebra identity chapters | 2–3 | Reciprocal ladders and x + 1/x results reached from a quadratic |
| Consistency of linear systems | 1–2 | Unique, infinite or no solution from the three coefficient ratios |
The third and fourth rows are the ones candidates underrate. Dividing an equation through by x to reach x + 1/x is a quadratic-equation move, and so is deciding whether a pair of lines meets.
What You Will Practice in the Quadratic Equation Chapter
Sum and product of the roots — the two numbers that answer everything
For ax² + bx + c = 0 with roots α and β, the sum is −b/a and the product is c/a. Every symmetric expression in the roots is reachable from those two alone, which is why the roots themselves are almost never worth finding.
| Wanted | Built from sum S and product P |
|---|---|
α² + β² | S² − 2P |
(α − β)² | S² − 4P, which is the discriminant over a² |
1/α + 1/β | S/P |
α³ + β³ | S³ − 3PS |
α²β + αβ² | PS — take the common factor out first |
α/β + β/α | (S² − 2P)/P |
Two of these are worth memorising as sentences rather than formulas. The gap between the roots squared IS the discriminant divided by a², so any question about how far apart the roots are is a discriminant question in disguise. And reciprocal roots mean the product is 1, which happens exactly when c = a.
The discriminant and the nature of the roots
D = b² − 4ac decides everything about what kind of roots exist, before any of them is found.
D > 0— two distinct real roots. IfDis also a perfect square, they are rational and the expression factorises over whole numbers.D = 0— the two roots merge into one repeated root, and the expression is a perfect square such as(2x − 3)². A zero discriminant is easy to misread as “no roots”; it means the opposite.D < 0— no real roots. The sum and product relations still hold and still give real answers, which is why a question can ask forα² + β²even here.
When a parameter sits inside the coefficients, the equal-roots condition D = 0 becomes an equation in that parameter. If the parameter appears squared you get two values and both must be reported; if the squared terms cancel you get one. Read which case you are in before assuming the answer count.
Signs and position of the roots
The product fixes the signs and the sum separates the remaining cases. A negative product means one root of each sign, and nothing else needs checking — a negative product also guarantees the roots are real. A positive product with a positive sum means both are positive; a positive product with a negative sum means both are negative. In each of those two cases the discriminant must still be tested separately, and it frequently trims the range a careless answer would allow.
For questions about where the roots sit relative to a number t, use the curve. With a positive leading coefficient the expression is negative strictly between its roots, so f(t) < 0 means t lies between them. To place both roots beyond t you need three conditions at once: D ≥ 0, f(t) > 0, and the turning point −b/2a on the correct side of t.
Building the equation whose roots are transformed
Find the new sum and the new product from the old ones, then write x² − (new sum)x + (new product) = 0 and clear any fractions at the end. The original roots are never needed.
| New roots | New sum | New product |
|---|---|---|
α², β² | S² − 2P | P² |
α³, β³ | S³ − 3PS | P³ |
1/α, 1/β | S/P | 1/P |
α+h, β+h | S + 2h | P + hS + h² |
The reciprocal row has a shortcut worth knowing: reversing the coefficients of the original equation produces the reciprocal-root equation directly, so 2x² − 7x + 3 = 0 becomes 3x² − 7x + 2 = 0. Note also that the shifted product is not P + h² — the cross term hS is the piece most often dropped.
Common roots
If two quadratics share ONE root, subtract them. The shared root satisfies both and therefore satisfies the difference, and the x² terms cancel to leave a linear equation that yields the root at once. Scale one equation first if the leading coefficients differ. The subtraction gives a candidate only, so substitute it back to find the unknown.
If they share BOTH roots, the two equations describe the same pair of numbers and can differ only by an overall scaling, so their coefficients are in proportion: a₁/a₂ = b₁/b₂ = c₁/c₂. Reading which of the two situations the question describes is half the work.
Factor theorem, remainder theorem and equations in disguise
If (x − p) is a factor of a polynomial then the polynomial is zero at x = p; a stated remainder means it equals that remainder instead. The same substitution answers both. When the divisor is (mx + n) the test value is the fraction −n/m, and when the divisor is a quadratic the remainder is of the form rx + s, which needs two substitutions to pin down.
A large family of questions is quadratic only after one move: a fractional equation cleared of denominators, a radical equation squared, a quartic in x², a repeated block replaced by a single letter, or an equation divided through by x to reach x + 1/x. In every one of these the last step is the one candidates forget — converting back, and discarding any value that breaks the original equation.
Consistency of linear equations in two variables
Compare the three ratios of a₁x + b₁y = c₁ and a₂x + b₂y = c₂:
a₁/a₂ ≠ b₁/b₂— the lines cross once, so there is exactly one solution whatever the constants are.a₁/a₂ = b₁/b₂ = c₁/c₂— the same line twice, so infinitely many solutions.a₁/a₂ = b₁/b₂ ≠ c₁/c₂— parallel and distinct, so no solution at all.
The constants are what separate the last two cases, so the third ratio is never a formality. When a parameter appears in several places, solve with two ratios and then TEST the answer in the third — a candidate that passes the first pair can still fail there.
Maximum and minimum of a quadratic expression
Complete the square: x² + bx + c = (x + b/2)² + (c − b²/4). A square is never negative, so with a positive leading coefficient the leftover constant is the minimum, reached at x = −b/2a; with a negative leading coefficient it is the maximum. Factor the leading coefficient out before completing the square, and read the question carefully — the position x and the value are different answers and both are offered.
Solved Examples — SSC CGL Quadratic Equation
Example 1 — a symmetric function without finding the roots. If α and β are the roots of x² − 7x + 12 = 0, find α² + β².
Read the two numbers off the coefficients: S = 7 and P = 12. Then α² + β² = S² − 2P = 49 − 24 = 25. The roots happen to be 3 and 4 here, but finding them was never necessary — and with roots like (5 ± √13)/2 it would have cost you the question.
Example 2 — equal roots giving two answers. For which values of k does x² + (k − 3)x + 9 = 0 have equal roots?
Equal roots means D = 0: (k − 3)² − 36 = 0, so (k − 3)² = 36 and k − 3 = ±6. That gives k = 9 or −3. Both are genuine — at k = 9 the equation is (x + 3)² and at k = −3 it is (x − 3)². Taking only the positive square root loses half the answer.
Example 3 — a common root. x² − 9x + k = 0 and x² − 11x + 3k = 0 share a root. Find the non-zero value of k.
Subtract: 2x − 2k = 0, so the shared root is x = k itself. Substituting into the first equation gives k² − 9k + k = 0, that is k(k − 8) = 0, so k = 8. Check it: x² − 9x + 8 = (x − 1)(x − 8) and x² − 11x + 24 = (x − 3)(x − 8), sharing the root 8.
Example 4 — transformed roots. α and β are the roots of 2x² − 7x + 3 = 0. Find the equation whose roots are 1/α and 1/β.
Here S = 7/2 and P = 3/2. New sum = S/P = 7/3; new product = 1/P = 2/3. So x² − (7/3)x + 2/3 = 0, and multiplying through by 3 gives 3x² − 7x + 2 = 0. Notice the coefficients have simply reversed — that shortcut works for reciprocal roots every time.
Example 5 — consistency of a pair of lines. For what value of k do 3x + 5y = 8 and 9x + ky = 24 have infinitely many solutions?
Infinitely many solutions needs all three ratios equal. The x-terms give 3/9 = 1/3 and the constants give 8/24 = 1/3, so the y-terms must match: 5/k = 1/3, giving k = 15. Had the constants been 8 and 25, that same k would have produced parallel lines and NO solution — the third ratio is what separates the two cases.
How the Quadratic Equation Chapter Tests Work
- 25 questions per test, with a full question palette — answered, skipped, marked for review, not visited.
- Optional 15-minute timer — the same sectional clock as the real paper, with it to build speed and without it while you are still learning the relations.
- Marking: +2 correct, −0.5 wrong, 0 unattempted — the same scheme as the real paper.
- Solutions, shortcut tricks and concept notes open after you submit, question by question.
- English and हिंदी, chosen at the start of every test.
- Free with a TrickySSC account — sign in once with Google or your mobile number, and every test is open to you.
How to Prepare Quadratic Equation for SSC CGL
- Write the sum and the product first, every single time. Before reading the rest of the question, put
S = −b/aandP = c/aon the page. A large share of this chapter is answered from those two lines alone. - Stop solving for the roots. If the question is symmetric in
αandβ, the roots are a detour. Finding them is the single biggest time loss in the chapter. - Learn the four identities cold —
S² − 2P,S² − 4P,S³ − 3PSandS/P. Everything else in the chapter is built by combining them. - Check where the parameter sits before counting answers. A parameter in the constant term usually gives one value; a parameter that ends up squared usually gives two. Reporting one when there are two is a common half-mark loss.
- Treat the discriminant as a range tool, not just a yes/no test. Questions asking for which values of
kthe roots are real, distinct, equal or of a given sign are discriminant questions with an inequality at the end. - For common roots, subtract; for both roots common, use proportion. Two different situations, two different methods, and the question always tells you which.
- Undo every substitution. Whether you set
y = x²,t = x + 1/xor named a repeated block, the answer asked for is inx. Handing back the helper variable is the most frequent error in the disguised-equation family. - Do Level 1 untimed first. The aim is the correct relation, not speed. Move to Level 2 with the 15-minute clock on — that is 36 seconds a question, the real Tier I pace.
- Verify against a real paper. Once Level 2 is consistent, attempt a previous year paper and then a full mock test under locked sectional timing.
All SSC CGL Chapter Wise Tests
Every chapter below has its own free Level 1 and Level 2 tests with full solutions.
Browse all 45 chapter tests — Maths (35) · Reasoning (10)
- Number System
- Rule of Divisibility
- Remainder Theorem
- Decimal & Fraction
- LCM & HCF
- Square & Cube Root
- Number Series (AP & GP)
- Power, Indices & Surds
- Algebraic Formula
- Algebraic Result
- Algebraic Expression & Identities
- Percentage
- Profit & Loss
- Discount & Marked Price
- Simple Interest
- Compound Interest
- Ratio & Proportion
- Partnership
- Average
- Problems on Ages
- Mixture & Alligation
- Time & Work
- Pipe and Cistern
- Time, Speed and Distance
- Quadratic Equation
- Boat and Stream
- Races
- Trigonometry
- Heights & Distances
- Geometry
- Mensuration
- Coordinate Geometry
- Probability
- Statistics
- Data Interpretation
- All Maths chapters →
SSC CGL द्विघात समीकरण (Quadratic Equation) चैप्टर टेस्ट — हिंदी में
द्विघात समीकरण SSC CGL बीजगणित का सबसे अधिक दोहराया जाने वाला अध्याय है। टियर I में इसके 1–2 प्रश्न सीधे आते हैं, और टियर II में 2–4। इसकी असली उपयोगिता इससे भी अधिक है, क्योंकि मूलों के योग और गुणनफल वाले संबंध बीजीय सर्वसमिकाओं में और विविक्तकर रैखिक समीकरणों की संगति में दोबारा काम आते हैं।
TrickySSC पर इस अध्याय के सभी टेस्ट हिंदी में उपलब्ध हैं — प्रश्न, विकल्प, विस्तृत हल और शॉर्टकट ट्रिक सब हिंदी में। दो स्तर हैं: लेवल 1 (SSC CGL स्तर) और लेवल 2 (SSC CGL से कठिन)। प्रत्येक टेस्ट में 25 प्रश्न, वैकल्पिक 15 मिनट का टाइमर और +2 / −0.5 की वही मार्किंग जो असली परीक्षा में होती है।
याद रखने योग्य नियम: ax² + bx + c = 0 के मूलों का योग −b/a और गुणनफल c/a होता है, इसलिए मूल निकालने की ज़रूरत प्रायः पड़ती ही नहीं। विविक्तकर D = b² − 4ac मूलों की प्रकृति तय करता है — D > 0 पर दो भिन्न वास्तविक मूल, D = 0 पर बराबर मूल, D < 0 पर कोई वास्तविक मूल नहीं। और यदि मूलों का गुणनफल ऋणात्मक हो तो दोनों मूलों के चिह्न अवश्य विपरीत होंगे।
SSC CGL Quadratic Equation — Frequently Asked Questions
How many quadratic equation questions are asked in SSC CGL?
Do I have to solve a quadratic to answer questions about its roots?
ax² + bx + c = 0 the roots add to −b/a and multiply to c/a. Anything symmetric in the two roots — their squares, their cubes, their reciprocals, the gap between them — can be built from those two numbers alone, without ever finding a root.What does the discriminant tell me?
D = b² − 4ac settles the nature of the roots. If D > 0 there are two distinct real roots; if D = 0 the two roots merge into one repeated root and the expression is a perfect square; if D < 0 there are no real roots at all. If D is also a perfect square the roots are rational.How do I find the value of k that makes the roots equal?
b² − 4ac = 0 with k substituted wherever it appears, then solve the equation that results. Watch where k sits: if it appears only in the constant you get one value, but if it appears squared — inside the middle coefficient, for instance — you get a quadratic in k and usually two answers, both of which must be reported.Two quadratics have a root in common. How do I find it?
x² terms cancel to leave a linear equation that hands the root over. Scale one equation first if the leading coefficients differ. Substitute the root back to find the unknown — the subtraction only gives a candidate.How do I write the equation whose roots are transformed?
x² − (new sum)x + (new product) = 0. Squaring the roots squares the product; taking reciprocals turns the sum into (α+β)/αβ; shifting each root by h adds 2h to the sum.Why are linear equations in two variables part of this chapter?
a₁/a₂ ≠ b₁/b₂ gives exactly one solution; all three equal gives infinitely many; the first two equal with the third different gives no solution at all.