Find a solution to the equation if possible.(adsbygoogle = window.adsbygoogle || []).push({});

Give the answer in exact form and in decimal form.

1 = 8cos(2x + 1) - 3

1 = 8tan(2x + 1) - 3

I don't know how to do this one.. but I know how to do the simpler ones like..

2 = 5sin(3x)

2/5 = sin(3x)

(sin^{-1}(2/5)) / 3 = 0.137172

Those are easier... but the one i've said before...

1 = 8cos(2x + 1) - 3 is tough..

1/8 = cos(2x + 1) - 3

3.125 = cos(2x + 1)

{[cos^{-1}(3.125)] / 2} - 1

Is this correct thus far, and if it is... cos^{-1}(3.125) is nonreal. So I guess there are no solutions...

How about this one?

1 = 8tan(2x + 1) - 3

1/8 = tan(2x + 1) - 3

3.125 = tan(2x + 1)

{[tan^{-1}(3.125)] / 2} - 1 = -0.369453

But, the right side doesn't evaluate to 1 when you plug -0.369453 in for x

I don't know where to go with these.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Trig Equation

**Physics Forums | Science Articles, Homework Help, Discussion**