
Amber D.
asked 04/16/21Solve over the interval [ 0 degrees , 360 degrees ). sin^2x * cosx = cosx
what I did for this question is move cosx to the other side of the equal sign to get sin^2x * cosx - cosx = 0 ... then cosx(sin^2x-1)=0 ... Cosx= 0 & sin^2x=1 , im unsure of what to do from here?
2 Answers By Expert Tutors
Raymond B. answered 04/17/21
Math, microeconomics or criminal justice
sin^2(x) = 1
sinx =+ or - sqr1 = + or -1
x = 90 or 270 degrees
cosx = 0
x= 90 or 270 degrees
Answer: x = 90 or 270 degrees or pi/2, or 3pi/2 radians
If you don't recognize how to get from cosx=0 to x=90, and 270, draw a unit circle, the more vertical the angle, the closer to 90 or 270, the smaller cosx is, until it reaches zero. or punch 0 into a calculator and then take the inverse cosine. Same with sinx=1. Use a calculator that has inverse trig functions., inverse sine and inverse cosine.
IF by chance, the problem really read sin2x and not sin^2x, the answers include more angles.

Yefim S. answered 04/16/21
Math Tutor with Experience
cosx(sin2x -1) = 0; - cos3x = 0, cosx = 0; x = 90° or x = 270°.
Answer: x = 90°, x = 270°
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John M.
I find many problems very difficult to understand because the " cut and paste" of the original problem skews the original problem and we are left trying to deceiver what the original equation was. Pay attention Wyzant...please.04/16/21