Question #5f32d

2 Answers
Feb 15, 2018

-cotxcscx

Explanation:

We have d/dx1/sinx

We can apply the quotient rule, that is, (f/g)', where Newton's notation is used and f and g are functions, is equal to (f'g-fg')/g^2.

Here, f=1 and g=sinx. We can input:

(d/dx(1)*sinx-1*d/dx(sinx))/sin^2x

We must find f' and g'.

d/dx1=0, so the above equation reduces to:

(-d/dxsinx)/sin^2x

Since d/dxsinx=cosx, we can input:

-cosx/sin^2x

Or:

-cosx/sinx*1/sinx

Since cosx/sinx=cotx and 1/sinx=cscx, this becomes:

-cotxcscx

Feb 15, 2018

-cotxcscx

Explanation:

"differentiate using the "color(blue)"chain rule"

"given "y=f(g(x))" then"

dy/dx=f'(g(x)xxg'(x)

"here "y=1/sinx=(sinx)^-1

rArrdy/dx=-(sinx)^-2xxd/dx(sinx)

color(white)(rArrdy/dx)=-cosx(sinx)^-2

color(white)(rArrdy/dx)=-cosx/(sin^2x

color(white)(rArrdy/dx)=-cosx/sinx xx1/sinx

color(white)(rArrdy/dx)=-cotxcscx