If sin x = -3/5 and pi <= x <=3pi/2, find cos x and tan x. I have the correct answers from the book (-4/5 and 3/4 respectively) but don't know how to work out the question. Thanks!

Expert Answers

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You should know that the values of sin and cos in the third quadrant are negative, hence the values of tan and cot are positive.

You need to use the basic trigonometric formula such that:

`sin^2x + cos^2x = 1 =gt cos x = - sqrt(1 - sin ^2x)`

Plugging sin x =`-3/5`  in the formula above yields:

`cos x = - sqrt(1 - (-3/5)^2) =gt cos x = -sqrt(16/25) =gt cos x = -4/5`

You should use the following formula...

(The entire section contains 2 answers and 221 words.)

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