Given the function f(x)=x2+2x+1, find:
a) f(−7)
Start with
f(x) = x2 + 2x + 1
1. Take out all the x's, and replace them with open parentheses
f( )= ( )2 + 2( ) + 1
2. Put -7's in the parentheses:
f(-7)= (-7)2 + 2(-7) + 1
Leave the left side as it is and simplify the right side:
f(-7)= 49 - 14 + 1
f(-7)= 36
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b) f(0)
Start with
f(x) = x2 + 2x + 1
1. Take out all the x's, and replace them with open parentheses
f( )= ( )2 + 2( ) + 1
2. Put 0's in the parentheses:
f(0)= (0)2 + 2(0) + 1
Leave the left side as it is and simplify the right side:
f(0)= 0 + 0 + 1
f(0)= 1
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c). f( 1/4 )
Start with
f(x) = x2 + 2x + 1
1. Take out all the x's, and replace them with open parentheses
f( ) = ( )2 + 2( ) + 1
2. Put 1/4's in the parentheses:
f(1/4) = (1/4)2 + 2(1/4) + 1
Leave the left side as it is and simplify the right side:
f(1/4) = 1/16 + 1/2 + 1
f(1/4) = 1/16 + 8/16 + 16/16
f(1/4) = 25/16
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d) f(0.3)
Start with
f(x) = x2 + 2x + 1
1. Take out all the x's, and replace them with open parentheses
f( )= ( )2 + 2( ) + 1
2. Put 0.3's in the parentheses:
f(0.3)= (0.3)2 + 2(0.3) + 1
Leave the left side as it is and simplify the right side:
f(0.3)= 0.09 + 0.6 + 1
f(0.3)= 1.69
Edwin
