25.
all squares are positive
thus f(-3) = (-3)^2-1 = 9-1 = 8
-3^2 = -9, but (-3)^2 = +9
when substituting in for x, to avoid mistakes, always enclose the value in ().
26.
f(3) = √(3+1)-2 = √4 - 2 = 2-2 = 0
27.
|x| = -x if x<0
|x| = x if x >= 0
so, |1-3| = |-2| = 2, not 4
do the addition first, then the ||.
Treat the || like special parentheses, or treat |x| like a function abs(x), so all the inside stuff is done first
|1-3| = 2
|1| + |-3| = 1+3 = 4
Check?
25. f(x)= x^2-1 ; -3, -2, -1, 0, 1, 2 ,3
=
f(x); -3^2-1=-10
f(x) ; -2^2-1=-5
f(x) ; -1^2-1=-2
f(x) ; 0^2-1=-1
f(x) ; 1^2-1=0
f(x) ; 2^2-1=3
f(x) ; 3^2-1=8
26. g(x); √(x+1)-2 ; x+-1, 0, 3, 8
g(x) ; √(-1+1)-2=-2
g(x) ; √(0+1)-2=-1
g(x) ; √(3+1)-2=4
g(x) ; √(8+1)-2=1
27. h(x)= |x-3| ; x=0,1,2,3,4,5,6
h(x); |0-3| =3
h(x); |1-3|=4
h(x); |2-3|=5
h(x); |4-3|=7
h(x); |5-3|=8
h(x); |6-3|=9
1 answer
1 answer