## help with these problems

Quadratic equations and inequalities, variation equations, function notation, systems of equations, etc.
netsfan549
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Joined: Wed Dec 19, 2012 5:36 am
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### help with these problems

The height,s, in feet of a rock thrown upward at an initial speed of 68ft/s from a cliff 48 ft above the ocean beach is given by the function s(t) = -16t2(squared) + 68t + 48, where t is the time in seconds/ Find the maximum height above the beach that rock willl attain.

On wet concrete the stopping distance, s in feet of a car traveling at v miles per hour is given by the function s(v) = 0.0o6v2 (squared) + 1.4v. What is the mximum speed at which a car could be traveling and still stop at a sign 52ft away?

Find two numbers whose difference is 86 and whose product is a minimum..

I dont get the problems. Can someone show me how to do it? show me and did you get answer. I really appreciate it. Thank you!

Posts: 136
Joined: Sun Feb 22, 2009 11:12 pm

### Re: help with these problems

The height,s, in feet of a rock thrown upward at an initial speed of 68ft/s from a cliff 48 ft above the ocean beach is given by the function s(t) = -16t2(squared) + 68t + 48, where t is the time in seconds/ Find the maximum height above the beach that rock willl attain.
find the vertex (thats where the max/min of quads are)
On wet concrete the stopping distance, s in feet of a car traveling at v miles per hour is given by the function s(v) = 0.0o6v2 (squared) + 1.4v. What is the mximum speed at which a car could be traveling and still stop at a sign 52ft away?
put in 52 for s and solve
Find two numbers whose difference is 86 and whose product is a minimum.
they show how to set this up here then find the vertex

buddy
Posts: 197
Joined: Sun Feb 22, 2009 10:05 pm
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### Re: help with these problems

The height,s, in feet of a rock thrown upward at an initial speed of 68ft/s from a cliff 48 ft above the ocean beach is given by the function s(t) = -16t2(squared) + 68t + 48, where t is the time in seconds/ Find the maximum height above the beach that rock willl attain.
complete the suqare or use the formula to get the vertex. h=t is the time of the max height. k=s is the max height.
On wet concrete the stopping distance, s in feet of a car traveling at v miles per hour is given by the function s(v) = 0.0o6v2 (squared) + 1.4v. What is the mximum speed at which a car could be traveling and still stop at a sign 52ft away?
52=0.06v^2+1.4v
solve for v.
Find two numbers whose difference is 86 and whose product is a minimum..
x-y=86, x-86=y, xy=x(x-86)=product
find vertex for max