#1

so i got two problems im a little stuck on for some reason. im to find the derivatives of each of the following:

1. y=[(x^2)-3x]cos(2x+10)

2. y= [sqrt(x)] / (x - pi)

ty in advance

1. y=[(x^2)-3x]cos(2x+10)

i only got to [(x^2)-3x][-sin(2x+1)] + [2x-3][cos(2x+1)] before completely forgetting what i had to do next

2. y= [sqrt(x)] / (x - pi)

and here i just couldnt think of wtf to do.

ty in advance

#2

I'm really tired and don't feel like working them out right now, but you need to use the quotient rule on the second one.

#3

I'm really tired and don't feel like working them out right now, but you need to use the quotient rule on the second one.

yeah i know that, but if i take the derivative of (x - pi) i would just get (1 - 1) no? and that just doesnt seem right to me

#4

yeah i know that, but if i take the derivative of (x - pi) i would just get (1 - 1) no? and that just doesnt seem right to me

No, the derivative of pi is zero because it's a constant.

#5

isnt the derivative of (x - pi) just 1.... the pi becomes 0

EDIT for spelling

EDIT for spelling

#6

yeah alright that makes some sense now, i just kept thinking of pi as a variable that would go to 1 just like x would.

#7

Goddammit does no one read the stickies?!?

Maths and help thread, my main man.

Maths and help thread, my main man.

#8

so i got two problems im a little stuck on for some reason. im to find the derivatives of each of the following:

1. y=[(x^2)-3x]cos(2x+10)i only got to [(x^2)-3x][-sin(2x+1)] + [2x-3][cos(2x+1)] before completely forgetting what i had to do next

2. y= [sqrt(x)] / (x - pi)and here i just couldnt think of wtf to do.

ty in advance

1.- you are missing that dx/dy cos = -sin u

**DU**so you are missing the derivate of the angle of cos

[(x^2)-3x][-sin(2x+1

**0**)

***2**] + [2x-3][cos(2x+1

**0**)]

Thats everything, just multiply everything, which im too lazy to do it in text

2.-

[[(x-pi)(1/2sqrt(x)) ] - [(sqrt(x))(1)]]/(x-pi) ^2

thats your derivate, if you want (your teacher surely does) simplify