Advertisements
Advertisements
Question
Evaluate the following: `(tan12°)/(cot78°)`
Solution
`(tan12°)/(cot78°)`
= `(tan(90° - 78°))/(cot78°)`
= `(cot78°)/(cot78°)`
= 1.
APPEARS IN
RELATED QUESTIONS
If 2 cos (A + B) = 2 sin (A - B) = 1;
find the values of A and B.
Solve for x : cos `(x/(2)+10°) = (sqrt3)/(2)`
If A = B = 60°, verify that: cos(A - B) = cosA cosB + sinA sinB
In right-angled triangle ABC; ∠B = 90°. Find the magnitude of angle A, if:
a. AB is `sqrt(3)` times of BC.
B. BC is `sqrt(3)` times of BC.
The perimeter of a rhombus is 100 cm and obtuse angle of it is 120°. Find the lengths of its diagonals.
Evaluate the following: sin28° sec62° + tan49° tan41°
Express each of the following in terms of trigonometric ratios of angles between 0° and 45°: cos72° - cos88°
If sin(θ - 15°) = cos(θ - 25°), find the value of θ if (θ-15°) and (θ - 25°) are acute angles.
If A, B and C are interior angles of ΔABC, prove that sin`(("A" + "B")/2) = cos "C"/(2)`
Prove the following: `(tan(90° - θ)cotθ)/("cosec"^2 θ)` = cos2θ