IDNLearn.com: Your trusted source for accurate and reliable answers. Join our interactive Q&A community and get reliable, detailed answers from experienced professionals across a variety of topics.
Sagot :
Let's solve the given problem step-by-step.
We start with the equation:
[tex]\[ x - \frac{1}{x} = 8. \][/tex]
First, we square both sides of the equation to simplify it further:
[tex]\[ \left( x - \frac{1}{x} \right)^2 = 8^2. \][/tex]
Expanding the left-hand side using the algebraic identity [tex]\((a - b)^2 = a^2 - 2ab + b^2\)[/tex], we get:
[tex]\[ x^2 - 2 \left( x \cdot \frac{1}{x} \right) + \frac{1}{x^2} = 64. \][/tex]
Simplifying the expression:
[tex]\[ x^2 - 2 + \frac{1}{x^2} = 64. \][/tex]
Next, we isolate [tex]\( x^2 + \frac{1}{x^2} \)[/tex] by adding 2 to both sides:
[tex]\[ x^2 + \frac{1}{x^2} = 64 + 2. \][/tex]
[tex]\[ x^2 + \frac{1}{x^2} = 66. \][/tex]
Now, we need to find the value of [tex]\( x^2 + \frac{1}{x^2} - 8 \)[/tex]. We substitute the value we just found:
[tex]\[ x^2 + \frac{1}{x^2} - 8 = 66 - 8. \][/tex]
[tex]\[ x^2 + \frac{1}{x^2} - 8 = 58. \][/tex]
Therefore, the correct answer is:
(ii) 58
We start with the equation:
[tex]\[ x - \frac{1}{x} = 8. \][/tex]
First, we square both sides of the equation to simplify it further:
[tex]\[ \left( x - \frac{1}{x} \right)^2 = 8^2. \][/tex]
Expanding the left-hand side using the algebraic identity [tex]\((a - b)^2 = a^2 - 2ab + b^2\)[/tex], we get:
[tex]\[ x^2 - 2 \left( x \cdot \frac{1}{x} \right) + \frac{1}{x^2} = 64. \][/tex]
Simplifying the expression:
[tex]\[ x^2 - 2 + \frac{1}{x^2} = 64. \][/tex]
Next, we isolate [tex]\( x^2 + \frac{1}{x^2} \)[/tex] by adding 2 to both sides:
[tex]\[ x^2 + \frac{1}{x^2} = 64 + 2. \][/tex]
[tex]\[ x^2 + \frac{1}{x^2} = 66. \][/tex]
Now, we need to find the value of [tex]\( x^2 + \frac{1}{x^2} - 8 \)[/tex]. We substitute the value we just found:
[tex]\[ x^2 + \frac{1}{x^2} - 8 = 66 - 8. \][/tex]
[tex]\[ x^2 + \frac{1}{x^2} - 8 = 58. \][/tex]
Therefore, the correct answer is:
(ii) 58
We appreciate your contributions to this forum. Don't forget to check back for the latest answers. Keep asking, answering, and sharing useful information. Your questions are important to us at IDNLearn.com. Thanks for stopping by, and come back for more reliable solutions.