solve for x

cot-1 (4x) + tan-1 (x) = 60 degrees

its so hard

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- Aug 24th 2010, 01:02 AMaeroflixSolving a trig equation.
solve for x

cot-1 (4x) + tan-1 (x) = 60 degrees

its so hard - Aug 24th 2010, 02:32 AMmathaddict
- Aug 24th 2010, 04:16 AMaeroflix
its kinda confusing. whats your point

- Aug 24th 2010, 08:17 AMSoroban
Hello, aeroflix!

The answers are truly ugly . . . but they check out!

I'll baby-talk through this for you . . .

Quote:

.[1]

Let

. . Then: .

So is in a right triangle with: .

. .

Hence: .

Then [1] becomes: . .[2]

We need this identity: .

Take the tangent of both sides of [2]:

. .

. .

So we have: .

. . which simplifies to: .