Mathematics

Trigonometric Identities

87 Questions

Trigonometric identities focus on solving equations using tangent, sine, and cosine properties. Questions involve half angle formulas and slope calculations. This topic is a staple in the quantitative aptitude section of major competitive examinations.

Tangent propertiesAngle formulasTrigonometric equationsHalf angle identitiesSlope calculations

Trigonometric Identities Questions

Multiple choice general knowledge
  1. 1/cosx

  2. 1/secx

  3. sinx/cosx

  4. cosx/sinx

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The tangent function is defined as tan x = sin x / cos x, which is the ratio of sine to cosine for the same angle. Options A and B are incorrect reciprocals, while D would be cotangent (cot x = cos x / sin x).

Multiple choice general knowledge
  1. 1+tanx

  2. 1/tanx

  3. 1/cosx

  4. 1/sinx

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The secant function is defined as sec x = 1/cos x, the reciprocal of cosine. Option D (1/sin x) would be cosecant (csc x), and options A and B are incorrect expressions. This is a fundamental reciprocal identity in trigonometry.

Multiple choice general knowledge
  1. infinity

  2. 1

  3. 0

  4. 3.14

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

tan(45°) = sin(45°)/cos(45°) = (√2/2)/(√2/2) = 1. At 45 degrees, sine and cosine have equal values, so their ratio is 1. Infinity would mean cos(45°) = 0, which is false.

Multiple choice general knowledge math & puzzles
  1. 0

  2. 5

  3. 10

  4. -10

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

To solve for p, first evaluate tan(45°) = 1. Then the equation becomes 3(1) + p = 8, which simplifies to 3 + p = 8. Subtracting 3 from both sides gives p = 5. This is a basic trigonometry substitution problem combined with linear equation solving.

Multiple choice general knowledge math & puzzles
  1. Sin x

    • Cos x
    • Sin x
    • Tan x
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The derivative of cos(x) is -sin(x). This follows from the rules of trigonometric differentiation. Conversely, the derivative of sin(x) is positive cos(x). Distractors like -cos(x) or -tan(x) do not follow the standard differentiation rules for this function.

Multiple choice general knowledge math & puzzles
  1. sec2 x

  2. csc2 x

  3. -csc2 x

  4. -sec2 x

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The derivative of tan x is sec^2 x. This follows from writing tan x = sin x/cos x and applying the quotient rule. The notation 'sec2 x' in option A is meant to represent sec²(x). Options B and C use csc (cosecant), which is unrelated to tan derivatives. Option D has the wrong sign.

Multiple choice general knowledge
  1. tan(90)

  2. cosec(0)

  3. sec(90)

  4. cot(90)

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Cot(90°) equals 0, which is a defined value. The other three trigonometric expressions are undefined because they involve division by zero: tan(90°) = sin(90°)/cos(90°) = 1/0, cosec(0°) = 1/sin(0°) = 1/0, and sec(90°) = 1/cos(90°) = 1/0.

Multiple choice general knowledge math & puzzles
  1. 0

  2. 1

  3. sin 90

  4. cos 0

  5. tan 45

  6. infinity

Reveal answer Fill a bubble to check yourself
B,C,D,E Correct answer
Explanation

tan 30 = 1/sqrt(3) and tan 60 = sqrt(3). Their product is 1. sin 90, cos 0, and tan 45 are all equal to 1. Therefore, all marked options are mathematically correct.

Multiple choice general knowledge math & puzzles
  1. 1/2

  2. 1/root(2)

  3. 1/3

  4. 1/root(3)

  5. root(3)/2

  6. none of above

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

If tan(2x) = 4sqrt(2)/7, use tan(2x) = 2tan(x)/(1-tan²x) to find tan(x) = sqrt(2)/4. Then sin(x) = tan(x)/sqrt(1+tan²x). Calculation: sin(x) = (sqrt(2)/4) / sqrt(1 + 2/16) = (sqrt(2)/4) / (3/sqrt(8)) = (sqrt(2)/4) * (2sqrt(2)/3) = 4/12 = 1/3.