f(x) equations....please help?

[Tara Marie]

Let f(x) = –2x2 – 5x + 3 and let g(x) = x2 – 10. Evaluate each of the following.

2a) (f + g)(5)...................2b) (f – g)(5)

 

[Deleted member 4993]

Let f(x) = –2x2 – 5x + 3 and let g(x) = x2 – 10. Evaluate each of the following.

2a) (f + g)(5) 2b) (f – g)(5)

Please show us what you have tried and exactly where you are stuck.

Please follow the rules of posting in this forum, as enunciated at:

https://www.freemathhelp.com/forum/threads/read-before-posting.109846/#post-486520

Please share your work/thoughts about this assignment.

 

[Dr.Peterson]

Please show your attempt, so we can see if there is something in particular that you are misunderstanding.

The main idea is that, given two functions f and g, we define a new function "f+g" as the function whose value for any input is the sum of the values of f and g. That is, (f+g)(x) = f(x) + g(x).

So find f(5) and g(5), and add (or subtract).

 

[Steven G]

Please use ^ before a power. For three squared you should write 3^2

 

[Otis]

Hi Tara Marie.

We use the caret symbol ^ to show exponents.

Please type x^2 instead of x2.

?

 

[HallsofIvy]

Let f(x) = –2x2 – 5x + 3 and let g(x) = x2 – 10. Evaluate each of the following.

As others have said, I presume you mean f(x)= -2x^2- 5x+ 3 and g(x)= x^2- 10.

2a) (f + g)(5)...................2b) (f – g)(5)

Do you understand that f(5)= -2(5^2)- 5(5)+ 3 and that g(5)= 5^2- 10.
Do you know how to calculate those?

I will assume that you know how to add and subtract!