1. cos 4theta = sin theta 2. tan 4theta = cot (20^0 + 20) Write the function sin (B + 35^0) in terms of its cofunction.
2cos^2 2x - 1 = sin x 2(1 - 2sin^2 x)^2 - 1 = sin x Now you have to solve a quartic in sin x. You know from the very 1st equation that pi/2 is a solution. The others are not so simple. Visit wolframalpha.com and enter solve cos 4x = sin x to see the graphs and the solutions.
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