SOLUTION: having problems with this equation: If f(t) = 2t^2 - 4t - 1, find f(2) then find f(-1) can someone explain this to me :(

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Question 90076: having problems with this equation:
If f(t) = 2t^2 - 4t - 1, find

f(2)
then find f(-1)
can someone explain this to me :(
Found 2 solutions by stanbon, Earlsdon:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
f(t) = 2t^2 - 4t - 1, find

f(2)
then find f(-1)
---------------
Substitute 2 in place of "t" to get:
f(2) = 2(2^2) - 4*2 -1
f(2) = 8 -8 -1
f(2) = 1
--------------------
Substitute -1 in place of "t" to get:
f(-1) = 2(-1)^2 -4*-1 -1
f(-1) = 2*1 +4 -1
f(-1) = 2 + 4 -1
f(-1) = 5
----------------------
Cheers,
stan H>

Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
If f%28t%29+=+2t%5E2-4t-1, find: f(2) the f(-1)
To do these problems, just substitute t = 2 to find f(2) and then t = -1 to find f(-1).
f%282%29+=+2%282%29%5E2-4%282%29-1
f%282%29+=+2%284%29-8-1 Simplify.
f%282%29+=+8-8-1
f%282%29+=+-1...and
f%28-1%29+=+2%28-1%29%5E2-4%28-1%29-1
f%28-1%29+=+2-%28-4%29-1 Simplify.
f%28-1%29+=+2%2B4-1
f%28-1%29+=+6-1
f%28-1%29+=+5