c) cos (315 °) d) sin (-30°) e) cos (330°) f) tan (150°) g) sin (225°) h) cos (210°)

Q: Find the exact value of sin 80° cos 20° - cos 80° sin 20°.

A: Use the identity sina-b=sin a·cos b-cos a·sin b.

Q: Find csc-1(4.3) (in radians).  (Hint: Use sin-1)

A:

Q: tan (sin-1)-cot (arccos

A: We need to find out the exact value of the given expression.

Q: what is cos(arccos(-3/7)) ?

A:

Q: 9tx 81-18

A: Since you have asked multiple questions in a single request so we will be answering only first…

Q: Evaluate the following expressions. Your answer must be an exact angle in radians and in the…

A:

Q: Explain the difference between sec(1/2) and cos -1 (1/2).  Make sure you use words to explain (you…

A: In this,we explain the difference between sec(1/2) and cos^-1(1/2) by using some calculations.

Ratios

A ratio is a comparison between two numbers of the same kind. It represents how many times one number contains another. It also represents how small or large one number is compared to the other.

Trigonometric Ratios

Trigonometric ratios give values of trigonometric functions. It always deals with triangles that have one angle measuring 90 degrees. These triangles are right-angled. We take the ratio of sides of these triangles.