ExamShortcut
high importance~3 Q in Tier 119 formulas⚡ 15 shortcuts5 subtopics

Ratios, the standard-value table, the three identities, complementary angles, value-putting and max-min values. Tier 1 reliably holds 2-4 trig questions and they fall almost mechanically to the value table, one identity, or a 3-4-5 style triangle — among the cheapest marks in the paper.

Track record in the exam

avg 2.0 Q / shift2024: 2–3 Q2025: 2 Q

Questions per shift in recent SSC CGL papers.

Test difficulty mix (72 questions)

19 easy40 medium13 hard

Question patterns exams keep repeating

Taken from previous-year papers. If a pattern is marked "very common", expect to see it in your exam.

Values at 30°, 45° and 60°

very common

A sum or product of sin, cos, tan at 0°, 30°, 45°, 60° or 90°.

Learn the small table: sin 30° = ½, cos 60° = ½, tan 45° = 1.

Put in the values and work out the sum.

Example

Find sin 30° + cos 60° + tan 45°.

sin 30° = ½

cos 60° = ½

tan 45° = 1

Sum = ½ + ½ + 1 = 2

Learn this in “Ratios and standard values” →

One ratio is given, find another

very common

"If sin θ = 3/5, find tan θ."

Draw a right triangle and write the given sides on it.

Find the third side with Pythagoras, then read off the ratio.

Example

If sin θ = 3/5, find tan θ.

sin θ = opposite ÷ hypotenuse, so opposite = 3, hypotenuse = 5

Third side = √(25 − 9) = 4 (adjacent)

tan θ = opposite ÷ adjacent = 3/4

Learn this in “Ratios and standard values” →

sec + tan (or cosec + cot) is given

very common

"If sec θ + tan θ = 3, find sec θ − tan θ."

The two always multiply to 1.

So the other one is 1 ÷ the given value.

Example

If sec θ + tan θ = 3, find sec θ − tan θ.

(sec θ + tan θ) × (sec θ − tan θ) = 1

3 × (sec θ − tan θ) = 1

sec θ − tan θ = 1/3

Learn this in “Fundamental identities” →

sin θ + cos θ is given

very common

"If sin θ + cos θ = 7/5, find sin θ cos θ."

Square both sides.

Use sin² θ + cos² θ = 1 to get the product.

Example

If sin θ + cos θ = 7/5, find sin θ cos θ.

Square: sin² + cos² + 2 sin cos = 49/25

sin² + cos² = 1, so 2 sin cos = 49/25 − 1 = 24/25

sin cos = 24/25 ÷ 2 = 12/25

Learn this in “Value-putting and given-ratio questions” →

tan θ is given, find a sin–cos fraction

very common

"If tan θ = 2, find (3 sin θ + cos θ)/(sin θ + cos θ)."

Divide the top and bottom by cos θ.

Every sin θ ÷ cos θ becomes tan θ. Then put in the number.

Example

If tan θ = 2, find (3 sin θ + cos θ) ÷ (sin θ + cos θ).

Divide top and bottom by cos θ:

(3 tan θ + 1) ÷ (tan θ + 1)

Put tan θ = 2: (3 × 2 + 1) ÷ (2 + 1)

= 7 ÷ 3 = 7/3

Learn this in “Value-putting and given-ratio questions” →

Angles that add up to 90°

very common

A long product like tan 10° × tan 20° × tan 70° × tan 80°.

Pair angles that add up to 90°.

Each pair multiplies to 1.

Example

Find tan 10° × tan 20° × tan 70° × tan 80°.

10° + 80° = 90°, so tan 10° × tan 80° = 1

20° + 70° = 90°, so tan 20° × tan 70° = 1

Product = 1 × 1 = 1

Learn this in “Complementary angles” →

Find the angle from an equation like tan = cot

very common

"If tan 2θ = cot(θ − 12°), find θ."

tan and cot of two angles are equal only when the angles add up to 90°.

Solve the simple equation.

Example

If tan 2θ = cot(θ − 12°), find θ.

The two angles add up to 90°

2θ + θ − 12° = 90°

3θ = 102°

θ = 34°

Learn this in “Complementary angles” →

Biggest value of a sin θ + b cos θ

very common

"Find the maximum value of 8 sin θ − 15 cos θ."

Maximum = √(a² + b²).

Minimum is the same number with a minus sign.

Example

Find the maximum value of 8 sin θ − 15 cos θ.

8² = 64 and 15² = 225

64 + 225 = 289

√289 = 17, so the maximum is 17

(the minimum is −17)

Learn this in “Maximum and minimum values” →

Smallest value of tan θ + cot θ

common

"Find the minimum value of tan θ + cot θ" (or tan² + cot²).

A number plus its reciprocal is never below 2.

It equals 2 when the number is 1 (θ = 45°).

Example

Find the minimum value of tan θ + cot θ for an acute angle θ.

At 45°: tan = 1, cot = 1, sum = 2

At 30°: 1/√3 + √3 is about 2.31, which is bigger

A number plus its reciprocal is never below 2

Minimum = 2

Learn this in “Maximum and minimum values” →

Two sides of a right triangle are given

common

Two sides of a right triangle are given. Asks the third side or a ratio.

Find the third side with Pythagoras.

The 8-15-17 and 3-4-5 triples often appear.

Example

A right triangle has legs 15 cm and 8 cm. Find the hypotenuse.

15² = 225 and 8² = 64

225 + 64 = 289

√289 = 17 cm

Learn this in “Ratios and standard values” →

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