Friday

January 30, 2015

January 30, 2015

Posted by **holly** on Monday, February 6, 2012 at 11:21pm.

y = sin x/

2 + cos x

- calculus -
**Reiny**, Monday, February 6, 2012 at 11:39pmdid you mean

y = sinx/(2+cosx) ??

I will assume you did.

dy/dx = ( (2+cosx)(cos) - sinx(-sinx) )/(2+cosx)^2

= (2cosx + cos^2 x + sin^2 x)/(2+cosx)^2

= (1 + 2cosx)/(2+cosx)^2

for a horizontal tangent, dy/dx = 0

or

1 + 2cosx = 0

cosx = -1/2

x = 2π/3 or x = 4π/3 , (120° or 240° )

the period of cosx = 2π

so general solutions:

x = 2π/3 + n(2π) or

x = 4π/3 + n(2π)

**Answer this Question**

**Related Questions**

calculus - Find the x-coordinates of all points on the curve f(x) = sin 2x &#...

calculus - For what values of x does the graph of f have a horizontal tangent? (...

calculus - 5) Find the points on the curve below at which the tangent is ...

calculus - Solve the given equation. (Enter your answers as a comma-separated ...

pre-calc help - Solve the given equation. (Enter your answers as a comma-...

Calculus - Find all values of x in the interval [0, 2π] that satisfy the ...

precalculus - Solve the given equation. (Enter your answers as a comma-separated...

Calculus - Use the given equation to answer the following questions. (Enter your...

Trigonometry - Use inverse trigonometric functions to find the solutions of the ...

Trigonometry - Use inverse trigonometric functions to find the solutions of the ...