QQuestion
Find x, if sin x = cos (x – 20°)
✓Answer
cos (x – 20°) = sin x
cos (x – 20°) = cos (90° – x)
Since cos A = cos B implies A = B or A + B = 360°, we equate:
x – 20° = 90° – x
Solving:
x + x = 90° + 20°
2x = 110°
x = 55°
Thus, x = 55°.
Related Questions
More WBBSE Moderate level questions
If 0° < θ < 90° then sin θ < sin²θ
If r cosθ = 2√3 and r sinθ = 2, then find the value of r and θ when 0° < θ < 90°.
If tan 2A = cot(A – 30°), then find the value of sec(A + 20°)
If sin (θ + 30°) = cos 15°, then find the value of cos 2θ.
If tan θ cos 60° = then the value of sin(θ - 15°) is _____.
If tan θ = find the value of sin θ.
If sin 17° = then show that sec 17° - sin 73° =
State True or False: The values of cos 36° and sin 54° are equal.
If ∠A and ∠B are complementary then ∠A + ∠B = _____
The Median of first (2n + 1) natural numbers is . Find the value of n.
The ratio of the length of radius of two solid right circular cylinders is 2:3 and the ratio of their heights is 5:3. Find the ratio of the area of curved surfaces.
If cos⁴θ – sin⁴θ = , find the value of 1 – 2 sin²θ.