1. Find all the solutions of the equation 3sin20(degrees) = cos2x(degrees) in the range 0(degrees) is less then or equal to x(degrees) which is less than or equal to 180(degrees).
2. A triangle has sides A-C =3cm
A-B = 5 cm
B-C = 4 cm
Find the area of the triangle
1 when you evaluate sin( 20 degrees) one obtains 0.349 and 3 times this is 1.026 which is greater than 1. However cos (2x) can only run from 1 to -1 in this range no matter the value of the arguement. So one of two things has happened. the equation given is incorrect or there is no x for which this equation is true.
Draw the triangle with B-C on the horizontal axis so that A is above the line of B-C.
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A trigonometric equation and area of triangle are solved.