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Write the number of solutions of the equation 4 sin x – 3 cos x = 7. |
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Answer» 4sin x – 3cos x = 7 4sin x – 7 = 3cos x Squaring both sides 16(sin x)2 + 49 – 56sin x = 9(cos x)2 16(sin x)2 + 49 – 56sin x = 9((sin x)2-1) 16(sin x)2 - 9(sin x)2 - 56sin x + 49 + 9 = 0 7(sin x)2 - 56sin x + 58 = 0 Solving the quadratic equation Sin x = 6.7774 or 1.2225 But we know that sinθ lies between [-1,1] So there are no solutions for this given equation |
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