+0  
 
0
632
2
avatar

Can 4cos2+3cos-2 be factored? if so what is it and how?

 

Thx! :)

 Jun 8, 2016

Best Answer 

 #1
avatar+129647 
+5

4cos^2 θ   + 3cos θ   - 2  

 

Let cos θ     =  x       and we have

 

4x^2 + 3x - 2   which cannot be factored....so......the original expression can't be factored, either

 

 

 

cool cool cool

 Jun 8, 2016
 #1
avatar+129647 
+5
Best Answer

4cos^2 θ   + 3cos θ   - 2  

 

Let cos θ     =  x       and we have

 

4x^2 + 3x - 2   which cannot be factored....so......the original expression can't be factored, either

 

 

 

cool cool cool

CPhill Jun 8, 2016
 #2
avatar+118629 
+5

Can 4cos2+3cos-2 be factored? if so what is it and how?

Is this what you mean?

 

\(4cos^2\theta+3cos\theta-2\\ let\;\;x=cos\theta\\ 4x^2+3x-2\\ put=0 \;and\; then\; use\;\;quadratic\;formula\\ x=\frac{-3\pm\sqrt{9+32}}{8}\\ x=\frac{-3\pm\sqrt{41}}{8}\\ 4cos^2\theta+3cos\theta-2=(cos\theta-\frac{-3+\sqrt{41}}{8})(cos\theta-\frac{-3-\sqrt{41}}{8})\\ 4cos^2\theta+3cos\theta-2=(\frac{8cos\theta+3-\sqrt{41}}{8})(\frac{8cos\theta+3+\sqrt{41}}{8})\\ 4cos^2\theta+3cos\theta-2=\frac{1}{64}(8cos\theta+3-\sqrt{41})(8cos\theta+3+\sqrt{41})\)

 Jun 8, 2016
edited by Guest  Jun 8, 2016

1 Online Users

avatar