Quandaries and Queries



My name is Chris and I'm a student having trouble solving for x in
this secondary level problem:

.387 = (.40 - .265x)/(sqrt(1-x2))

Any help you could give me would be much appreciated.





Hi Chris,

I would first multiply both sides by sqrt(1-x2) to get

0.387 sqrt(1-x2) = 0.4 - 0.265 x

Now square both sides

0.3872 (1 - x2) = (0.4 - 0.265 x)2
0.149769 - 0.149769 x2 = 0.16 - 0.212 x + 0.070225 x2

Simplify this exprression and use the general quadratic to solve for x. This will give you two values for x. Make sure that you verify that they are solutions by substituting into the original equation. Squareing both sides of the equation may have introduced an extraneous root.



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