WILL FAN AND MEDAL FOR ANSWER.
7.
If sinθ=4/5, what is the value of cosθ in quadrant 1?
A.
9/25
B.
16/25
C.
3/5
D.
5/4

Question

WILL FAN AND MEDAL FOR ANSWER.
7.
If sinθ=4/5, what is the value of cosθ in quadrant 1?
A.
9/25
B.
16/25
C.
3/5
D.
5/4

anonymous · Answer

careful here

anonymous · Answer

it is not $$\sin^2(4/5)+\cos^2(x)=1$$ it is $$(\frac{4}{5})^2+\cos^2(x)=1$$

anonymous · Answer

easier to draw a right triangle |dw:1446778812861:dw|

anonymous · Answer

there is a picture of an angle whose sine is $\frac{4}{5}$ find the missing side via pythagoras, or just remember the mother of all right triangles 3 - 4 - 5
then you can take any trig ratio you like

anonymous · Answer

Thank you for pointing out my mistake.