SOLUTION: Given that f(x)=x2-2x-7, find and simply f(a-1) and f(a+h)-f(a).

Algebra ->  Algebra  -> Polynomials-and-rational-expressions -> SOLUTION: Given that f(x)=x2-2x-7, find and simply f(a-1) and f(a+h)-f(a).      Log On

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Question 34931: Given that f(x)=x2-2x-7, find and simply f(a-1) and f(a+h)-f(a).
Answer by longjonsilver(2297) About Me  (Show Source):
You can put this solution on YOUR website!
+f%28x%29=x%5E2-2x-7+

Things like this are nice and straight forward:
+f%28a-1%29=%28a-1%29%5E2-2%28a-1%29-7+
+f%28a-1%29=a%5E2-4a-4+

+f%28a%2Bh%29=%28a%2Bh%29%5E2-2%28a%2Bh%29-7+
+f%28a%2Bh%29=a%5E2%2B2ah%2Bh%5E2-2a-2h-7+

and +f%28a%29=a%5E2-2a-7+

So, +f%28a%2Bh%29+-+f%28a%29+=+a%5E2%2B2ah%2Bh%5E2-2a-2h-7+-+%28a%5E2-2a-7%29+
+f%28a%2Bh%29+-+f%28a%29+=+a%5E2%2B2ah%2Bh%5E2-2a-2h-7+-a%5E2%2B2a%2B7+
+f%28a%2Bh%29+-+f%28a%29+=+2ah%2Bh%5E2-2h+
+f%28a%2Bh%29+-+f%28a%29+=+h%5E2%2B2ah-2h+

jon.