Scorel 2/5 Penaltys 1 off Evaluate Quadratic Functions Question Examples Given \( f(x)=4 x^{2}+2 \), find \( f(-9) \) Answer

To find \( f(-9) \), simply substitute \(-9\) into the function: \[ f(-9) = 4(-9)^{2} + 2 = 4(81) + 2 = 324 + 2 = 326. \] So \( f(-9) = 326 \)! Quadratic functions are like roller coasters—full of ups and downs! Did you know that their graphs are parabolas? This means they can open either upwards (like a smile) or downwards (like a frown), determined by the coefficient of the \( x^2 \) term. In this case, since 4 is positive, the parabola opens upwards! When evaluating quadratic functions, a common mistake is forgetting to square the input value first. Remember, the order of operations matters! Always square the number before multiplying by the coefficient and adding any constants. This simple tip can help avoid calculation errors and lead to a correct answer every time!