Q. f(x)=x2(x+2)(x−2)(x−5) has zeros at x=−2,x=0,x=2, and x=5.What is the sign of f on the interval −2<x<5 ?Choose 1 answer:(A) f is always positive on the interval.(B) f is always negative on the interval.(C) f is sometimes positive and sometimes negative on the interval.
Identify Zeros:f(x)=x2⋅(x+2)⋅(x−2)⋅(x−5) has zeros at x=−2, x=0, x=2, and x=5. To find the sign of f on the interval -2 < x < 5, we need to look at the sign of each factor in the interval.
Analyze x2: For x2, any value of x (except 0) will give a positive result since squaring a number always results in a positive number.
Analyze (x+2): For (x+2), any value of x greater than −2 will make this factor positive.
Analyze (x−2): For (x−2), any value of x greater than 2 will make this factor positive, but since we're looking at the interval -2 < x < 5, this factor will be negative for -2 < x < 2.
Analyze (x−5): For (x−5), any value of x less than 5 will make this factor negative, which applies to the entire interval -2 < x < 5.
Calculate Sign -2 < x < 2: Now, let's multiply the signs of each factor together for the interval -2 < x < 2. We have a positive from x2, a positive from (x+2), a negative from (x−2), and a negative from (x−5). Positive times positive times negative times negative equals positive.
Calculate Sign 2 < x < 5: Next, for the interval 2 < x < 5, we have a positive from x2, a positive from (x+2), a positive from (x−2), and a negative from (x−5). Positive times positive times positive times negative equals negative.
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