Question

(d) 3 cos 80°. cosec 10° + 2 cos 59º. cosec 31°​

Answer 1

Answer:

5

Step-by-step explanation:

From properties of trigonometry:

• cosecA = sec(90 - A)
• secA = 1/cosA

Therefore,

• cos80°.cosec10°

= > cos80°. sec(90 - 10)

= > cos80°.sec80°

= > cos80°/cos80°

= > 1

And,

• cos59°.cosec31°

= > cos59°. sec(90 - 31)

= > cos59°.sec59°

= > cos59°/cos59°

= > 1

Thus,

= > 3 cos 80°. cosec 10° + 2 cos 59º. cosec 31°

= > 3(1) + 2(1) = 3 + 2

= > 5