Hi Guys, I am trying to investigate a function, during the process I need to solve this equation: sin(x)+cos(2x)=0 in the region 0<=x<=2*Pai How do I solve it ? thanks !
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Use the identity to turn your equation into a quadratic, which you can then solve.
Start by writing it as and recall that . So we have . You should be able to solve it with ease now. Hint: if then (where is an integer, or zero).
I used the quadratic idea, I did t=sin(x) and got t1=-0.5 and t2=1 thus, I got: sin(x)=-0.5 and sin(x)=1 my solution is x=pai/2 and x=11/6*pai but there should be another one at x=3.63, I have no idea why....
Originally Posted by WeeG I used the quadratic idea, I did t=sin(x) and got t1=-0.5 and t2=1 thus, I got: sin(x)=-0.5 and sin(x)=1 my solution is x=pai/2 and x=11/6*pai but there should be another one at x=3.63, I have no idea why.... at and
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