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Find cos x if sin^2x-1/cos x = -1 a. –1 b. 2 c. 1 d. 0

User Xufeng
by
6.5k points

2 Answers

4 votes

Answer:

C

Explanation:

Edge2021

User Tobias Heinicke
by
7.8k points
3 votes

Answer: 1

Explanation:

Alright, lets get started.

The given expression is :


(sin^2x-1)/(cosx)=-1

As per Pythagorean identity,


sin^2x + cos^2 x = 1

taking 1 to left side and
cos^2 x to right side


sin^2 x-1=-cos^2x

Now plugging the value of
sin^2 x-1 in given expression


(-cos^2x)/(cosx) =-1

cosx will be cancelled, so


-cosx=-1

Multiplying -1 in both sides, it will equal to


cos x= 1 ........................ Answer (C)

Hope it will help :)

User Kevin Nagurski
by
7.4k points