Evaluating Functions Evaluating Functions Evaluating functions is just

  • Slides: 8
Download presentation
Evaluating Functions

Evaluating Functions

Evaluating Functions Evaluating functions is just like evaluating algebraic expressions. Evaluate has the word

Evaluating Functions Evaluating functions is just like evaluating algebraic expressions. Evaluate has the word “valu” hidden inside. When you see the word “evaluate” – you know that your answer is going to be a value.

Evaluating Functions The only difference with functions is that the ‘notation’ (the way it

Evaluating Functions The only difference with functions is that the ‘notation’ (the way it is written) is different. f(x)=x+3 find f ( - 2 ) is just another way of saying y = x + 3 find y when x = - 2

Evaluating Functions Actually, function notation is easier. Even if you didn’t know anything about

Evaluating Functions Actually, function notation is easier. Even if you didn’t know anything about it, it sort of looks like they put the - 2 where the x was! f(x)=x+3 find f ( - 2 )

Bird’s nesting To evaluate this function, we’re going to use a technique that I

Bird’s nesting To evaluate this function, we’re going to use a technique that I call “bird’s nesting”. It may sound silly but it will save you a world of hurt when it comes to sign mistakes.

f(x)=x+3 find f ( - 2 ) I’m going to rewrite the expression, but

f(x)=x+3 find f ( - 2 ) I’m going to rewrite the expression, but every time I get to a letter, I’m going to insert an open ( ) instead the proverbial bird’s nest. f(-2)=( )+3

Now let’s fly our little feathered friend into his nest! f ( - 2

Now let’s fly our little feathered friend into his nest! f ( - 2 ) = (- 2 ) + 3 f (- 2 ) = 1 See how the ( ) keeps everything straight!

Evaluating Functions Expect a value for your answer. Replace all the letters with (

Evaluating Functions Expect a value for your answer. Replace all the letters with ( ) Fly the ‘bird’ into its ‘nest’. Follow the order of operations and the rules of signed numbers.