Ok.. so I've been stuck on a problem for a while now and have no clue how to even start this problem it's 3sin^2X+5cosX=4 It would be much appreciated if someone could explain to me how I even start to solve this problem
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Originally Posted by StephAnnie Ok.. so I've been stuck on a problem for a while now and have no clue how to even start this problem it's 3sin^2X+5cosX=4 It would be much appreciated if someone could explain to me how I even start to solve this problem You need to use the Pythagorean identity $\displaystyle \sin^2(x)=1-\cos^2(x)$ this reduces the equation to $\displaystyle 3(1-\cos^2(x))+5\cos(x)-4=0 \iff 3\cos^2(x)-5\cos(x)+1=0$ So this is quadratic in form. Can you finish from here
Thank you soo much for your help!!
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