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Help with Pre-Calc.?
Explain how you find instantaneous velocity and find it for s(t) = -3 + 4t^2 when t = 5 seconds.
6 Answers
- cidyahLv 73 years ago
s(t) =-3+4t^2
s'(t) = 8t
v(t)= 8t
when t=5 , v(t) = 8(5) = 40 sec
You find the instantaneous velocity by taking the derivative of s(t) and substituting t=5
- ?Lv 73 years ago
If this is "PRE" calculus, I suppose we are not just to write s'(t) = 8t = 40 m/s.
How about this:
s'(5) = lim h-->0 [-3 + 4(5+h)^2 - (-3 + 4*5^2)] / h }
= lim h-->0 (40h / h) = 40.
The difficulty with your question is that we (at Yahoo!Answers) don't know what techniques you are "allowed" to use.
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- billrussell42Lv 73 years ago
s(t) = -3 + 4t²
assuming s is distance
v = ds/dt
v = 8t
at t = 5, v = 8•5 = 40 units/s
