SOLUTION: In this function, f(x)= -2(x-1)²(x+3) : - f(x) touches the x-axis at ? - f(x) crosses the x-axis at ?

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: In this function, f(x)= -2(x-1)²(x+3) : - f(x) touches the x-axis at ? - f(x) crosses the x-axis at ?      Log On


   

Question 901042: In this function, f(x)= -2(x-1)²(x+3) :
- f(x) touches the x-axis at ?
- f(x) crosses the x-axis at ?
Answer by josgarithmetic(39626) About Me  (Show Source):
You can put this solution on YOUR website!
The zeros are also critical values. Check the sign of each interval.

The zeros are 1 and -3. You can see this because f is shown in its factored form. The intervals on x to check signs for f are:
-infinity%3Cx%3C-3;
-3%3Cx%3C1;
1%3Cx%3Cinfinity.
Pick ANY value in each interval and test the sign of f(x).

You should find, according to each listed interval:
Positive, negative, negative.

Can you conclude what that means? Note that around the value x=1, the value for f is still negative. Sign did not change there.




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