Question

Given sinθ = -3/4 and θ is in quadrant 4, find the following:

cosθ

tanθ

sin (-θ)

cos (-θ)

Answer 1

draw the picture

Answer 2

sin is the opposite over the hypotenuse

Answer 3

and use pythagorus to find the unknown side ( which turns out to be sqrt(7) )

Answer 4

so now we have the triangle we can read of the values

Answer 5

cos(theta) = sqrt(7) / 4

Answer 6

What is sqrt? I haven't learned that...

Answer 7

tan(theta ) = -3 / sqrt(7) , note: tan isneagtive in the 4th quadrant

Answer 8

sqaure root lol

Answer 9

\[\sqrt{7} ?\] , you must know

Answer 10

Oh okay thank you lol I got confused

Answer 11

ow, sin(-theta) - -sin(theta ) because sin is an odd function

so sin(- theta ) = 3/4

Answer 12

and cos(-theta) = cos(theta) , because cos is even ,

so cos(-theta) = sqrt(7) / 4

Answer 13

thank you SOOOOO much! You're a big help. I really appreciate it!