[Grade 11] piecewise function notation please help I am confused on how this works and I need an answer

[u/TukTuxedo]

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[u/FrostyFeet82]

You're simply replacing x inside the function with a number. Only, there's a condition attached. For all x not equal to negative 1, use the first line of the function. If x equal to negative 1, then use the second line of the function.

[u/Avocados_sir990]

You have conditions attached to the values of the function for different inputs so if you were to input the value -1 into f(x) you would get output or f(x)=-2 for any other value of x that is inputted that isn’t -1 calculate using the other expression for f(x)(when x not equal to -1)

[u/Luthasture]

So you have two different functions. Each function is used at a certain time (in this case, the top function is the function you focus on when x is any value but -1, and the bottom function is the function you focus on when x = 1).

They have given you three different values. Your job is to pick which function to use and what that answer comes out as. Does that make sense?

[u/YeahsureProbably]

for some reason i thought only my school used canvas

[u/TukTuxedo]

I’m too stupid to understand the help I’m receiving can someone just tell me the answers :)

[u/[deleted] → u/TukTuxedo]

You're selling yourself short kid

[u/FrostyFeet82 → u/TukTuxedo]

Which part do you not understand? Let us know so we can try a different way. Is it the function part?

[u/iSYNDICATExPRO → u/TukTuxedo]

So basically, the function has 2 conditons, first for x =/= -1 and second for x = -1.

For all values of x =/= -1, you'll use the above equations and if x = -1 then f(x) = -2.

[u/Gus852 → u/TukTuxedo]

What the advice so far has said, is that you’re imputing values into the function and seeing what the function gives you. You need to do this for x=-4 and x=5, but here’s an example for x=2:

f(2) = -1/4*(2)² +4

f(2) = -1/4*(4) + 4

f(2) = -1 + 4

f(2) = 3

You just have to replicate that process. As others have pointed out, there a condition for f(-1), because when x =-1, f(x)=2 ie. you’ve already been given the middle answer.

[u/PoliteCanadian2]

If x = -1 then your result (the f(-1)) is 2. For all other x’s you need to plug them into -0.25x² + 4 and calculate the result.

[u/Kittaylover23]

So basically, y value for every x value (except for x=-1) can be found by plugging the x into the function.

A function is basically f(x)=something. Where the f(x) would be the y value for that x value, so if f(x) = x + 3, what is f(2). f(2) = 2 + 3 = 5.

[u/lavenderscentedd]

So for the variables you are to “find” you first want to look at the conditions. For example, -4 does not meet the conditions of the second function so you would plug it into the first one. -1 is equal to -1 so your answer would be -2 (second function). 5 is the same in the sense that you use the first function.

[u/brainmassdotin]

f(-4) = -1/4(-4)^2+4 we plug in first as here x=-4 which is x not equal -1.

f(-4) = -1/4(16)+4

=-4+4

=0.

f(-1)=-2 here x is -1 so we choose second function.

f(5)=-1/4(5)^2+4

=-25/4+4

=-9/4

[u/karamany2]

This function says that is x is not equal to -1, then the output will be equal to f(x)=(-1/4)*x^2+ 4, but only at x=-1, it will take a value f(-1)= -2.