Question

If cos(θ) = -5/17 and θ is in quadrant III, find sin(θ). Give your answer to four decimal places.

If sin(θ) = -15/17 and θ is in quadrant III, find cos(θ). Give your answer to four decimal places.

Answer 1

So I have to figure out what x is?

Answer 2

Yes - use pythagoras
the sine will be x / 17

Answer 3

cosine is adjacent / hypotenuse ?

Answer 4

-5 / 17

Answer 5

yes - and sine = opposite / hypotenuse

Answer 6

x = - sqrt(17^2 - 5^2)

Answer 7

-16.2481

Answer 8

yes

Answer 9

now do I do the same thing for the second problem

Answer 10

similar thing yea

Answer 11

sine is opposite / hypotenuse?

Answer 12

right

Answer 13

is that how it would be?

Answer 14

yea