Răspunsuri

2014-08-04T19:55:15+03:00
1)
 5^{ x^{2} } = 5^{1}

=> x² = 1
=> x = ± 1
x₁ = 1
x₂ = -1

2)
 log_{2} (1 -  \sqrt{x+1} ) = -1


=> 1 - √(x + 1) = 2⁻¹
1 - √(x + 1) = 1 / 2
- √(x + 1) = 1/2 - 1
-√(x + 1) = -1/2    l  * (-1)
√(x + 1) = 1 / 2
x + 1 = ± 1 / 4
Ridicarea la putere poate sa introduca solutii false
a)
x + 1 = 1/4
x = 1/4 - 1 = -3/4

b)
x + 1 = -1/4
x = -1/4 - 1 = -5/4