How do I simplify? sin²x-sinx2/sin²x-4

2 Answers
Mar 20, 2018

The simplified expression is #sinx/(sinx+2)#.

Explanation:

Your input question wasn't really clear, so I'll assume you meant this:

#(sin^2x-2sinx)/(sin^2x-4)#

To solve this question, factor out like terms on the top and bottom like you are solving a quadratic. Then, cancel the ones that are in common with the bottom and the top of the fraction.

Here's what that process looks like:

#color(white)=(sin^2x-2sinx)/(sin^2x-4)#

#=((sinx)^2-2sinx)/((sinx)^2-2^2)#

#=((sinx)(sinx-2))/((sinx)^2-2^2)#

#=((sinx)(sinx-2))/((sinx+2)(sinx-2))#

#=((sinx)color(red)cancelcolor(black)((sinx-2)))/((sinx+2)color(red)cancelcolor(black)((sinx-2)))#

#=sinx/(sinx+2)#

I don't know if this is what you wanted, but this is the answer to the problem I understood. If this isn't what you were asking for, please write a comment letting me know so I can change this.

Mar 20, 2018

#sinx/(sinx+2)#

Explanation:

GCF and difference of squares:
#x^2-x= x(x-1)#
#(x^2-4)= (x+2)(x-2)#

Apply them to this:
#(sin²x-2sinx)/(sin²x-4)=#

#(sinxcancel((sinx-2)))/((sinx+2)cancel((sinx-2)))=#

#sinx/(sinx+2)#