I need help with these two math questions. 1. Evaluate the function f(x)=x2+7x-9 at the givenvalues of the independent variable and simplify. A- f(-8), B- f(x+2) c- f(-x) 2. Let f(x)=x2-x-2 and g (x)= 6x+5. Find g(1) andf(g(1)) Could you please help me Thanks I need help with these two math questions. 1. Evaluate the function f(x)=x2+7x-9 at the givenvalues of the independent variable and simplify. A- f(-8), B- f(x+2) c- f(-x) 2. Let f(x)=x2-x-2 and g (x)= 6x+5. Find g(1) andf(g(1)) Could you please help me Thanks
Explanation / Answer
1. f(x) = x^2 +7x -9 so, a) f(-8) = (-8)^2 + 7(-8) - 9 = 64 - 56 - 9 = -1 b) f(x+2) = (x+2)^2 + 7(x+2) - 9 = (x^2 + 4x +4) + (7x + 14) - 9 = x^2 +4x + 7x + 4 + 14 - 9 = x^2 +13x + 9 c)f(-x) = -x^2 - 7x - 9 2. If f(x)=x2-x-2 and g (x)= 6x+5Then, Find g(1) and f(g(1)) a) g(1) = 6(1) +5 = 11 - Same method as before.. b) f(g(1)) = (6(1) +5)^2 - (6(1)+5) - 2 = 121 - 11 - 2 =108 - For problems such as this you begin with the functionclosest to the varaible of interest (in this case (1)). Onceyou enter this variable into the function g, you would next plugthe function g (in this case (6x+5) into all the x variables infunction f (in this case x^2-x-2) and solve accordingly. Hope this Helps! These are all funtions so to answer simply replacethe different variables given in the question with the(x) variables that are present in the original function (x^2+7x -9)