Supposing that x + 1 is the base of logarithm, we'll
impose the constraints of existence of logarithms:
x+ 1
>0
x + 1different from
1
x different from
0
x>-1
x^2+3x-14
> 0
x^2+3x-14 = 0
x1 =
[-3+sqrt(9 + 56)]/2
x1 = (-3 +
sqrt65)/2
The range of admissible values of x for the
logarithms to exists, is: ((-3 + sqrt65)/2 ;
+infinitte).
We'll solve the
equation:
x^2+3x-14 =
(x+1)^2
We'll expand the square from the right
side:
x^2+3x-14 = x^2 + 2x +
1
We'll eliminate x^2:
3x-14 =
2x + 1
We'll subtract 2x + 1 both
side:
3x - 2x - 14 - 1 = 0
x -
15 = 0
x =
15
Since the value of x belongs to the
interval of admissible values, we'll accept as solution of the equation x =
15.
No comments:
Post a Comment