How do you simplify (sinx/(1-cosx))+((1-cosx)/sinx)(sinx1cosx)+(1cosxsinx)?

2 Answers
Mar 1, 2016

sinx/(1-cosx)+(1-cosx)/sinx = 2cscxsinx1cosx+1cosxsinx=2cscx

Explanation:

sinx/(1-cosx)+(1-cosx)/sinxsinx1cosx+1cosxsinx

Multiply the first term by sinx/sinxsinxsinx and the second term by (1-cosx)/(1-cosx)1cosx1cosx

= sin^2x/(sinx(1-cosx))+(1-cosx)^2/(sinx(1-cosx))=sin2xsinx(1cosx)+(1cosx)2sinx(1cosx)

Group terms with common denominators

=(sin^2x+(1-cosx)^2)/(sinx(1-cosx))=sin2x+(1cosx)2sinx(1cosx)

Expand (1-cosx)^2(1cosx)2

=(sin^2x+1-2cosx+cos^2x)/(sinx(1-cosx))=sin2x+12cosx+cos2xsinx(1cosx)

Apply the identity sin^2x+cos^2x=1sin2x+cos2x=1

=(2-2cosx)/(sinx(1-cosx))=22cosxsinx(1cosx)

Factor out 22 from the numerator

=(2(1-cosx))/(sinx(1-cosx))=2(1cosx)sinx(1cosx)

Cancel common terms from the numerator and denominator

=2/sinx=2sinx

Apply the definition of the cosecant function (cscx = 1/sinxcscx=1sinx)

=2cscx=2cscx

Mar 1, 2016

2/sinx 2sinx

Explanation:

Write with a common denominator

(sin^2x + (1 - cosx)^2)/(sinx(1 - cosx)) sin2x+(1cosx)2sinx(1cosx)

=( sin^2x + 1 - 2cosx + cos^2x)/(sinx(1- cosx))=sin2x+12cosx+cos2xsinx(1cosx)

=( sin^2x + cos^2x + 1 - 2cosx)/(sinx(1-cosx))=sin2x+cos2x+12cosxsinx(1cosx)

[using the identity : sin^2x + cos^2x = 1] sin2x+cos2x=1]

then becomes :( (1 + 1 - 2cosx))/(sinx(1-cosx))(1+12cosx)sinx(1cosx)

= (2(1 - cosx))/(sinx(1-cosx))=2(1cosx)sinx(1cosx)

=( 2cancel(1-cosx))/(sinxcancel(1-cosx)) = 2/sinx