SOLUTION: Solve the following questions for 0. Unless otherwise specified, give all solutions as exact radian measures 20cos^2 0-5 cos 0 + 10 = 13

Question 1036368: Solve the following questions for 0. Unless otherwise specified, give all solutions as exact radian measures
20cos^2 0-5 cos 0 + 10 = 13
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
Solve the following questions for 0. Unless otherwise specified, give all solutions as exact radian measures
20cos^2 0-5 cos 0 + 10 = 13
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Sub x for the cosine
20x^2 - 5x - 3 = 0

Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)

Quadratic equation (in our case ) has the following solutons:

For these solutions to exist, the discriminant should not be a negative number.

First, we need to compute the discriminant : .

Discriminant d=265 is greater than zero. That means that there are two solutions: .

Quadratic expression can be factored:

Again, the answer is: 0.531970514902493, -0.281970514902493. Here's your graph:

==================
cos = as stated above
========
Use a calculator to find the principal values.
No exact solution is possible.

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