For the first question find dy/dx at x equals 0. This will be the gradient of the tangent. You can find the normal using this.

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- Aug 19th 2011, 09:16 PM #1

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## I need help with some question please!!!! :)

The equation of a parabola is given by (x^2) -4x - 2y + 8 =0*

Find the equation of the normal at (0,4)*

2. A woman walks 120 meters on a bearing of 312 then turns and walks for a further 96 meters on a bearing of 056*

How far is she from her starting point,

And find the bearing of the woman from her starting point.*

3.

Y=-(x-1)^2*

Y= 2x-10*

Intersect in forth quadrant, find the point of intersection.*

Find x intercepts and hence find the area under the curve*

Two straight roads run from point O. One heads west while the other heads south.*

Person A is 24km west of point O whilst person A is 18km south of O.*

Person A walks at 2km/h towards o, where as person B walks 4km/h away from O.*

Show that after t hours, the area A km^2 of triangle AOB is given by:*

A=216+30t-4t^2*

Calculate rate of change in the area after 1 hour

When does this triangles are start to decrease?

the area of the sector of a circle, radius r units, subtending an angle of (theta) at the center is 100(pie)cm^2*

Show that the perimeter of the sector can be given by*

P= 2r + 200/r*

Find the radius of the circle that makes the perimeter of the sector a minimum.*

*

- Aug 19th 2011, 09:25 PM #2

- Aug 19th 2011, 11:28 PM #3
## Re: I need help with some question please!!!! :)

Please post according to the forum rules:

See rule #4 and rule #8: http://www.mathhelpforum.com/math-he...hp?do=vsarules.

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