Posted by **Tammy** on Wednesday, May 2, 2007 at 2:57pm.

Find the derivative of

a) y=cos (x/2)

b) yx-3x^2 +6 = y^4 + x

a) -sin (x/2)(2+x)/2^2

-sin(x/2)(x/2)

b) x dy/dx + y - 6x = 4y^3 dy/dx + 3x^2

dy/dx (x -4 y^3) = 3x^2 -y +6x

dy/dx = (3x^2 -y +6x)/(x -4 y^3)

I used inplicit differation for part b

are these correct? Thanks for your help in advance!

your first answer makes no sense.

you are simply finding the derivative of

y = cos (1/2)x

which is

y'=-1/2 sin (x/2)

your second equation:

If your last term of the equation was a typo and it was x^3, then you are correct.

I like the way you showed the first line of your implicit derivative, but according to that line the last term must have been x^3 instead of x.

## Answer this Question

## Related Questions

- Calculus 12th grade (double check my work please) - 1.)Find dy/dx when y= Ln (...
- TRIG! - Posted by hayden on Monday, February 23, 2009 at 4:05pm. sin^6 x + cos^6...
- tigonometry - expres the following as sums and differences of sines or cosines ...
- Mathematics - Trigonometric Identities - Let y represent theta Prove: 1 + 1/tan^...
- algebra - Can someone please help me do this problem? That would be great! ...
- calculus - Could someone check my reasoning? thanx Find the derivative of the ...
- calculus - Find the points on the curve y= (cos x)/(2 + sin x) at which the ...
- trig - Reduce the following to the sine or cosine of one angle: (i) sin145*cos75...
- Math - Calculus - The identity below is significant because it relates 3 ...
- Trig - Find sin(s+t) and (s-t) if cos(s)= 1/5 and sin(t) = 3/5 and s and t are ...

More Related Questions