Search 83,261 tutors
FIND TUTORS
Ask a question
0 0

Functions Question!!

Tutors, please sign in to answer this question.

2 Answers

A function is a rule that you apply to a variable.  In this case the variable,x, represents a number and the rules just tells you what to do with the number.  For f(4), you do: 6*(4)-2  = 24-2 = 22, so f(4) = 22
 
Do you think you can do it for the other function?  Remember to substitute the number given (-2) and apply the rule: 4x^2 -x +5 
 
edit: that negative was hard to see:  sorry, though if you follow the steps with the correct value the answer works out
The notation f(4) means f(x=4).  So just plug in 4 wherever there is an x:
 
f(x) = -6x - 2
 
f(4) = -6(4) - 2
 
f(4) = -24 - 2
 
f(4) = -26
 
For f(x) = 4x2 - x + 5
 
f(-2) = 4(-2)2 - (-2) + 5
 
f(-2) = ?