SOLUTION: The directions say "Solve each Equation for Principal values of x. Express solutions in degrees" the problem says sinx=1+cos^2x. I changed cos^2x to 1-sin^2x so I have sinx=1+1-sin
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-> SOLUTION: The directions say "Solve each Equation for Principal values of x. Express solutions in degrees" the problem says sinx=1+cos^2x. I changed cos^2x to 1-sin^2x so I have sinx=1+1-sin
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Question 699813: The directions say "Solve each Equation for Principal values of x. Express solutions in degrees" the problem says sinx=1+cos^2x. I changed cos^2x to 1-sin^2x so I have sinx=1+1-sin^2x but I'm not sure what to do next. My Teacher has done a lot of factoring with problems like these and then solves for the two solutions, but I don't get how he factors them. Answer by mananth(16946) (Show Source):
You can put this solution on YOUR website! sinx = 1+cos^2x
sinx = 1+1-sin^2x
sin x= 2-sin^2x
Rearrage
sin^2x+sinx-2 =0
factor the quadratic equation
sin^2x+2sinx-sinx-2=0
sinx(sinx+1)-1(sinx+2)=0
(sinx+1)(sinx-1)=0
sin x= -1 OR xinx =1
