Evaluate the function f (a) = 2a^2 + a if f (-a)

To get the answer simply substitute the given value to the given equation

after substituting the value, instead of f (a) it will then become f (-a)

change the value of every "a" in the equation according to the given; which is - a.

after substituting the given the answer will become f (-a) = - 2a^2 - a

solution:

f (a) = 2a^2 + a if f (-a)

f (-a) = 2 (-a) ^2 + (-a)

f (-a) = - 2a^2 - a from addition the operation became subtraction because in math (+) (-) = (-) "positive time negative is negative".