Thread: calc 1 question

point moves along a curve y=2x^2+1 in such a way that the y value is decreasing at the rate of 2 units per sec. at what rate is x changing when x=3/2.

y' = 4x so F'(3/2)= m = 6
so slope=6 and f(3/2) = y= 11/2

point slope formula = y-(11/2) = 6(x-(3/2)) = y= 12x/2 -7/2

so do I set x=0 to find rate of change for x?

Originally Posted by weezie23

point moves along a curve y=2x^2+1 in such a way that the y value is decreasing at the rate of 2 units per sec. at what rate is x changing when x=3/2.

y' = 4x so F'(3/2)= m = 6
so slope=6 and f(3/2) = y= 11/2

point slope formula = y-(11/2) = 6(x-(3/2)) = y= 12x/2 -7/2

so do I set x=0 to find rate of change for x?

nope. implicit differentiation is what is needed here. what you are doing is for a whole other class of problem. are you sure you're getting what's going on in class?


..............differentiate with respect to time



now, you are told , you are asked for , just solve for it