Question

an equation of the tangent line to the function y^4=-5x^2-3x^2-3x+12. at the point (1,1).

a)y=-7x+6
b)y=2x-3
c)y=-6x+7
d) -6x-8
e) y=-2x+1

Answer 1

Have you found y' yet?

Answer 2

i have but it is very messy. I was wondering if the y^4 might be a typo. i am not sure

Answer 3

derivative of y^4 is 4y^3*y' by chain rule and power rule

Answer 4

you could go ahead and combine the like terms -5x^2-3x^2 first before differentiating though

Answer 5

that is if they were suppose to be like terms

Answer 6

i am going to bet there is a typo

Answer 7

i tried to do find the tangent line and i am not getting any of the choices.. i dont know

Answer 8

well your problem has y^4=-5x^2-3x^2-3x+12
i'm kinda wondering if you meant y^4=-5x^3-3x^2-3x+12

Answer 9

i copied it down in class... maybe i did...

Answer 10

in that case your answer is listed

Answer 11

let me see your derivative work for
differentiating y^4=-5x^3-3x^2-3x+12

Answer 12

the derivative of that is 4y^3=-15x^2-6x-3

Answer 13

you must use chain rule for the y^4

Answer 14

\[4y^3 \cdot y'=-15x^2-6x-3 \]

Answer 15

oh so implicitly differentiate

Answer 16

now you can replace the x's with 1 and the y's with 1
and solve for y'

Answer 17

well whenever i see x and y together most always y is a function of x

Answer 18

most always

Answer 19

it could be the other way around
are both x and y could be functions of time

Answer 20

but yeah I assume here y is a function of x

Answer 21

so is it c

Answer 22

lol yes

Answer 23

haha thanks!!!