Help me with this question (1 Viewer)

[112244]

Please help me with this 3-part question (Differential Calculus:Rules for differentiation):

Q1) Find the coordinates of the points on the curve y=x²-5x+6 at which the tangent:
A) makes an angle of 45 degrees with the X-axis.
B) is parallel to the line with the equation 3x+y-4=0
C) is perpendicular to the line with the equation 2y-x+3=0

Thanks in advance

 

[Hikari Clover]

回复: Help me with this question

y=x²-5x+6
y'=2x-5

A)angle of 45 degrees with the X-axis, means gradient = 1
y'=2x-5=1
x=3
(3,0)

B)rearrange 3x+y-4=0 ----> y=-3x+4
gradient=-3
y'=2x-5=-3
x=1
(1,2)

C)2y-x+3=0 ------> y=1/2x-3/2
gradient=1/2
y'=2x-5=1/2
x=11/4
(11/4,do it urself)
:rofl:

 

[jannny]

Shouldnt that be, y` = -2 ( perpendicular not parallel)

-2 = 2x - 5
2x = 3
x = 3/2

then sub back to equation 2y - x +3 = 0
to get y.

 

[Hikari Clover]

回复: Re: Help me with this question

oh.....

my mistake...........