Q. Given the function f(x)=2x2−3x3, find the value of f(−21) in simplest form.Answer:
Substitute x: Substitute x with −(21) in the function f(x)=2x2−3x3.f\left(-\left(\frac{\(1\)}{\(2\)}\right)\right) = \(2\left(-\frac{1}{2}\right)^2 - 3\left(-\frac{1}{2}\right)^3
Calculate square and cube: Calculate the square and cube of −(1/2). (−1/2)2=(1/4) and (−1/2)3=−(1/8)
Replace exponents in function: Replace the exponents in the function with their calculated values.f(−21)=2(41)−3(−81)
Multiply coefficients by exponents: Multiply the coefficients by the calculated exponents.f(−21)=12⋅41−13⋅(−81)f(−21)=21−(−83)
Simplify expression: Simplify the expression by adding the fractions.f(−21)=21+83To add these fractions, find a common denominator.
Find common denominator: The common denominator for 2 and 8 is 8.Convert 21 to a fraction with a denominator of 8.21=84
Convert 21 to fraction: Add the fractions with the common denominator.f(−(21))=84+83f(−(21))=87
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