1) For which of the following functions is f(-5) = 2 ? a)f(x) = x +7 b) f(x) = 2x-6 c) f(x) = 3x+5 d) none of these

Question

2) Which of the following is a function? a)(-4,1), (1,8), (-4,2) b)(-4,1), (1,-8), (-2,2) c)(-4,1),(1,-8), (1,2) d) none of these

3) what is the relationship between the lines y=-8x +5 and y =-3x -7 ?
4) evaluate i^14

I think

1- a
2- don't understand
3 -don't understand
4 - -1

can someone veridy & assist me on this ?

Answer 1

1. correct
4. correct

2.
A function is a relation which relates the elements of two sets (of numbers) such that any element of the first set is related to exactly one element of the second set.
For example:
A={1,2,3}, B={4,5,6}
f: A->B is a function which relates elements of set A to elements of set B.
If we define f by (1,4),(2,6),(3,5), then the relation f is a function, since it satisfies the stipulation that any element in A is related to exactly one element in B.

On the other hand,
if we define:
g : A-> B such that
(1,4),(1,6),(2,5),
then g is not a function because element 1 of set A is related to two elements of B (4 and 6). So in this case, g is not a function.

3. The two lines are not parallel, so they intersect somewhere in space.
They are not parallel because the slopes are different (8 and -3).