Posted by **Shirley** on Sunday, March 22, 2009 at 6:21pm.

Im having trouble with this.

Find an equation of the tangent line to the parabola at the given point and find the x-intercept of the line.

x^2=2y (4,8)

- Pre-Calculus -
**drwls**, Sunday, March 22, 2009 at 7:34pm
y = (1/2) x^2

The slope of the curve is dy/dx = x

At x = 4, the slope is 4.

For a line though (4,8) with slope = 4, the equation is

(y-8) = 4(x-4)

Rewrite that in standard y = mx + b form.

- Pre-Calculus -
**GanonTEK**, Sunday, March 22, 2009 at 7:35pm
well, from the above equation y = (x^2)/2

to get an equation of a line you need a slope and a point. You have a point and to get the slope we need to get dy/dx

and sub in the value for x in the point given [in this example 4]

Then sub your point (x1,y1) and the slope (m) into

y - y1 = m(x - x1)

and then just tidy up

Hope that helps

## Answer This Question

## Related Questions

- Pre-Cal - Find an equation of the tangent line to the parabola at the given ...
- Algebra - graph the equation x-3=y (where do I plot the points?) find the ...
- math - i have more than one question so if u no any of the answers please tell ...
- Calculus AB - Could someone please help me with these tangent line problems? 1) ...
- Calculus - I have a two part question that pertains to a curve (r(x)) and its ...
- Math - I had an assignment containing 45 problems, and I am unsure of 4, can you...
- Math - I had an assignment containing 45 problems, and I am unsure of 4, can you...
- MATH - I had an assignment containing 45 problems, and I am unsure of 4, can you...
- calculus - 5. Let f be the function given by f(x) = x3- 7x + 6. a. Find the ...
- Calculus AB - Sorry but I've got a lot of problems that I don't understand. 1) ...

More Related Questions