Question

Find the exact value of cos (arcsin (five divided by thirteen)).

Answer 1

Are you allowed to use a calculator?

Answer 2

no

Answer 3

Ah, right. We need a triangle

Answer 4

sin = opposite/hypotenuse

Answer 5

cos = adjacent/hyp
so 12/13

Answer 6

12 comes from pythagoras' theory, 13^2 - 5^2 = 12^2
so = 12.

Answer 7

so is the final answer 12/13?

Answer 8

Yep, thats correct.

Answer 9

thank you

Answer 10

Cool cool :)

Answer 11

how would I do this using a calculoator?

Answer 12

Something along the lines of pressing shift + sin or arcsin to get arcsin 5/13, then putting the answer into memory, pressing cos and recalling the previous answer from memory. My calculator works like this, but yours might be a bit different :)

Answer 13

ok thanks