- #1
Jaco Viljoen
- 160
- 9
Homework Statement
g(x)=√(5+x)-x
a) Write down D(g)
b) Solve the equation
√(5+x)-x=3
Homework Equations
√(5+x)-x=3
The Attempt at a Solution
a)
x∈ℝ: x>-5
b)[/B]
√(5+x)-x=3
√(5+x)=x+3
(5+x)=(x+3)^2
(5+x)=(x+3)(x+3)
(5+x)=x^2+6x+9
x^2+5x+4=0
(x+4)(x+1)
x=-4 or x=-1
√(5-4)--4=3
√(1)+4=3 False
√(5-1)--1=3
2+1=3 True
x=-1
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