Question

Implicit Differentiation with trig.

Answer 1

Would cos(2y)82=1 be the correct start?

Answer 2

Or is it cos(2y*y')*2=1 ? Not sure if y or x is the one we're taking the derivative of.

Answer 3

Cos(2y)*2(dy/dx) = 1

Answer 4

Okay i guess that makes sense, so to solve for dy/dx. It would be 1/2cos(2y) ?

Answer 5

yea 1/(2Cos(2y))

Answer 6

yup.

Answer 7

Alright yeah i got it. Now lets see if if i can find the slope at (0,pi/2)

Answer 8

just plug in 0 for x and pi/2 for y and u're done.

Answer 9

just plug in pi/2 for y.

Answer 10

you have no more x, it became 1 when you differentiated :P

Answer 11

1/(2 * cos(2 *pi/2)) = 1/ (2 * cos(pi)) = ?

Answer 12

Yeah cos at pi/2 is 0. so (2*0) is 0. But cos of 0 is 1, so 2cos(1) = 2. so Its 1/2?

Answer 13

jaja.. plugging it in still doesn't hurt.. just because you can't

Answer 14

Ummm.....

Answer 15

still need help?

Answer 16

Is it 1/2? Or did i mess it up?

Answer 17

Messed up.

Answer 18

@Jhannybean I was asking @SgtSausage

Answer 19

Cos pi is -1

Answer 20

1/(2 *-1)

Answer 21

Oh 2 *pi/2 = pi thats where i messed up. I was taking cos of pi/2

Answer 22

Never evaluate until you're done fully simplifying the problem.

Answer 23

fully done simplifying the problem*

Answer 24

^said Jhannybean to herself

Answer 25

Yeah so its actually -1/2 them

Answer 26

LOL ik i mess up quite a bit...

Answer 27

I'm the pr0 of messing up and stupid mistakes.

Answer 28

:D.. it's math, we all do

Answer 29

Thanks everyone : ) I'm getting slightly closer to not failing my calc test tomorrow :P