If sin A = 15/17, What is cos A?

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Question

If sin A = 15/17, What is cos A?

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amistre64 · Answer

what do you get when you apply the pythag thrm?

amistre64 · Answer

sin^2 + cos^2 = 1

anonymous · Answer

$$\sin^2A + \cos^2A =1$$

anonymous · Answer

same lol

amistre64 · Answer

:)

anonymous · Answer

i just have no idea how to do trig.

amistre64 · Answer

this is more algebra than trig

anonymous · Answer

cosA = 8/17

amistre64 · Answer

another way is to see this is a right triangle whose sides are 15 and ? and a hypot of 17 to wit:

cos = sqrt(17^2 -15^2)/17

anonymous · Answer

this is the only problem i don't get, and it's multiple choice. the answers are:                  
A) 0.47 B) 0.53 C) 0.88 D) 2.13

anonymous · Answer

A

anonymous · Answer

i just don't get these yet. our class isn't even in this subject as a whole yet. we have about 3 more chapters to do before we get to cos, sin, tan

amistre64 · Answer

another brand of flavor is:

sin A = 15/17

A = sin-1(15/17)

cos A = cos(sin-1(15/17))

anonymous · Answer

i am very thankful for all the help, you guys are amazing! math is a weak subject for me, but i like it