THe distance between the road of a bridge and the top part of its arch is 3m. If the arch of the bridge is given by the equation h(x)=7x-x2, find the height of the bridge. Remember the last 2 in the equation is a superscript or exponent of x. ASAP
2006-10-02 04:40:41 · 2 answers · asked by ys2i7love 2 in Education & Reference ➔ Homework Help
isn't that 7x(2)-2x+3
2006-10-02 18:19:28 · update #1
i mean 7x(2)-x(2)+3
2006-10-02 18:20:48 · update #2
it right: the equatio would be 7x(2)-x(2)+3
2006-10-08 09:47:04 · answer #1 · answered by Fawad Ahmad 2 · 0⤊ 0⤋
Take the first derivative of h(x). This is 7-2x. Set it to zero to find the maximum -- this is x = 7/2. Now stick it into h(x) to find the height = 7*(7/2) - (7/2)^2 -- so the height is 12.25 meters.
You are told the height of the bridge over the road is three meters in the first sentence. This means that the road is 9.25 meters from the bottom of the bridge.
2006-10-02 11:52:24 · answer #2 · answered by Ranto 7 · 0⤊ 0⤋