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If sin θ=.55 what is the value of cos θ and explain why

User Babu James
by
7.6k points

1 Answer

3 votes

Answer:


cos(\theta)=(+/-)0.84

Explanation:

we know that


sin^2(\theta)+cos^2(\theta)=1 ----> by trigonometric identity

we have


sin(\theta)=0.55

substitute


(0.55)^2+cos^2(\theta)=1


cos^2(\theta)=1-(0.55)^2


cos^2(\theta)=0.6975


cos(\theta)=(+/-)√(0.6975)


cos(\theta)=(+/-)0.84

Remember that

If the sine of angle theta is positive, then the angle theta lie on the I Quadrant or II Quadrant

therefore

If the angle theta is on the I Quadrant the cosine will be positive

If the angle theta is on the II Quadrant the cosine will be negative

User Wildroid
by
8.2k points

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