Question

Find the equation of tangent on the curve.
y=x3 at point (2,8).​

Answer 1

Answer:

y = 12 x − 16

 

Explanation:

m tangent = d y/ d x  at x = 2

d y/ d x = 3x ^2  

at x = 2  d y /d x = 3 ( 2 ) ^2 = 12

 ⇒ y − 8 = 12 ( x − 2 ) ← point-slope form  

⇒ y = 12 x − 16 ← slope-intercept form

Explanation:

Answer 2

Answer:

∙

x

m

tangent

=

d

y

d

x

at x = 2

d

y

d

x

=

3

x

2

at x = 2

d

y

d

x

=

3

(

2

)

2

=

12

⇒

y

−

8

=

12

(

x

−

2

)

←

point-slope form

⇒

y

=

12

x

−

16

←

slope-intercept form