If x4 + 16 = 8x2, then find the value of x6 – 6x3.
Answer
Correct Answer : a ) 16
Explanation :According to the question
x4 + 16 = 8x2
⇒ x4 - 8x2 + 16 = 0
⇒ (x2)2 – 2 * x2 * 4 + 42 = 0
⇒ (x2 - 4)2 = 0
⇒ x2 = 4
⇒ x = ±2
Take x = 2
x6 – 6x3
Substitute the value of x
⇒ (2)6 – 6(2)3
⇒ 64 – 48
⇒ 16
Hence, (a) is the correct answer.
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