SOLUTION: If f(x)=x^2+5, find f(a+h)-f(a). This one I'm having so much trouble with. I think it is 2ah+h2+10 but not sure. thanks for checking again.

Algebra ->  Points-lines-and-rays -> SOLUTION: If f(x)=x^2+5, find f(a+h)-f(a). This one I'm having so much trouble with. I think it is 2ah+h2+10 but not sure. thanks for checking again.      Log On


   

Question 43372This question is from textbook algebra and trigonometry with analytic geometry
: If f(x)=x^2+5, find f(a+h)-f(a). This one I'm having so much trouble with. I think it is 2ah+h2+10 but not sure. thanks for checking again. This question is from textbook algebra and trigonometry with analytic geometry

Found 2 solutions by longjonsilver, psbhowmick:
Answer by longjonsilver(2297) About Me  (Show Source):
You can put this solution on YOUR website!
Given that +f%28x%29=x%5E2%2B5+

then +f%28a%2Bh%29=%28a%2Bh%29%5E2%2B5+
+f%28a%2Bh%29=a%5E2%2B2ah%2Bh%5E2%2B5+

and +f%28a%29=a%5E2%2B5+

hence f(a+h)-f(a) is +%28a%5E2%2B2ah%2Bh%5E2%2B5%29+-+%28a%5E2%2B5%29+
+f%28a%2Bh%29-f%28a%29+=+a%5E2%2B2ah%2Bh%5E2%2B5+-+a%5E2+-+5+
+f%28a%2Bh%29-f%28a%29+=+2ah%2Bh%5E2%2B5+-+5+
+f%28a%2Bh%29-f%28a%29+=+2ah%2Bh%5E2+
+f%28a%2Bh%29-f%28a%29+=+h%282a%2Bh%29+

jon.

Answer by psbhowmick(878) About Me  (Show Source):
You can put this solution on YOUR website!
f%28x%29=+x%5E2+%2B+5

So, when x = a replace 'x' by 'a'
then, f%28a%29=+a%5E2+%2B+5

Also, when x = (a+h) replace 'x' by (a+h)
then, f%28a%2Bh%29=+%28a%2Bh%29%5E2+%2B+5
or f%28a%2Bh%29=+%28a%2Bh%29%5E2+%2B+5

f%28a%2Bh%29+-+f%28a%29+=+%28%28a%2Bh%29%5E2+%2B+5%29+-+%28a%5E2+%2B+5%29
or f%28a%2Bh%29+-+f%28a%29+=+a%5E2+%2B+2ah+%2B+h%5E2+%2B+5+-+a%5E2+-+5
or f%28a%2Bh%29+-+f%28a%29+=+2ah+%2B+h%5E2

So your answer is incorrect.