please help?
1 find the inverse function. Show all steps.
f(x) = 5x – 7 Then find f ^ -1 (-27)
2 f(x) = 3x + 2 g(x) = x – 4 find (fg)(x) and simplify. please show your work
回答 (4)
1)f(f^-1(x)=x ,rule
5f^-1(x) )-7 =x
F^-1(x)=(x+7)/5
f^-(-27) =(-27+7)/5=-20/5=-4
2) f^-1(x) =(x-2)/3
3)g^-1(x)=x+4
f(g(x))=f(x-4)=5(x-4) -7=5x-20-7=5x-27
1 find the inverse function. Show all steps.
f(x) = 5x – 7 Then find f ^ -1 (-27)
Let y = 5x - 7
Solve for x
y + 7 = 5x
x = (y + 7)/5
swap x and y
y = (x + 7)/5
so f^-1(x) = (x + 7)/5
f^-1(-27) = (-27 + 7)/5
= -20/5
= - 4
2 f(x) = 3x + 2 g(x) = x – 4 find (fg)(x) and simplify. please show your work
Does fg(x) stand for f*g(x) or fog(x)
I am assuming it is fog(x) = f(g(x))
fg(x) = f(g(x))
= f(x - 4)
= 3(x - 4) + 2
= 3x - 12 + 2
= 3x - 10
Or
f*g(x) = (3x + 2)(x - 4)
= 3x^2 - 12x + 2x - 8
= 3x^2 - 10x - 8
1. y = 5x -7
x = 5y -7
x + 7/5 = 5y/5
y =( x + 7) / 5
y = (-27 +7) / 5
y = -4
2. (3x + 2)(x - 4)
= 3x^2 - 12x + 2x -8
= 3x^2 -10x -8
1.
Let y = f(x) = 5x - 7 and g (y) = x
g is inverse of f
5x = y + 7
x = [ y + 7 ] / 5
g (y) = [ y + 7 ] / 5
g (x) = [ x + 7 ] / 5
2.
f [ g(x) ] = f [ x - 4 ] = 5x - 27
收錄日期: 2021-04-21 23:59:48
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