Respuesta :

we are given

[tex] \frac{tanx}{secx-1}- \frac{sinx}{1+cosx}=2cot(x) [/tex]

Firstly , we will simplify left side

and make it equal to right side

Left side:

[tex] \frac{tanx}{secx-1}- \frac{sinx}{1+cosx} [/tex]

we know that

sec(x)=1/cos(x)

[tex] \frac{tanx}{(1/cosx)-1}- \frac{sinx}{1+cosx} [/tex]

[tex] \frac{tanx*cosx}{1-cos(x)}- \frac{sinx}{1+cosx} [/tex]

[tex] \frac{sin(x)}{1-cos(x)}- \frac{sinx}{1+cosx} [/tex]

now, we can take common denominator

[tex] \frac{sin(x)(1+cosx)}{(1-cos(x))(1+cosx)}- \frac{sinx(1-cosx)}{(1+cosx)(1-cosx)} [/tex]

[tex] \frac{sin(x)(1+cosx)}{1-cos^2(x)}- \frac{sinx(1-cosx)}{1-cos^2x} [/tex]

[tex] \frac{sin(x)(1+cosx)}{sin^2x}- \frac{sinx(1-cosx)}{sin^2x} [/tex]

now, we can cancel sinx

[tex] \frac{(1+cosx)}{sinx}- \frac{(1-cosx)}{sinx} [/tex]

[tex] \frac{(1+cosx)-(1-cosx)}{sinx} [/tex]

now, we can simplify it

[tex] \frac{1+cosx-1+cosx}{sinx} [/tex]

[tex] \frac{2cosx}{sinx} [/tex]

so, we get

[tex] 2cot(x) [/tex]

we can see that left side is equal to right side

[tex] \frac{tanx}{secx-1}- \frac{sinx}{1+cosx}=2cot(x) [/tex]............Answer