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2 years ago

If a+1/a=3 then find the value of a-1/a

Mathematics

1 answer:

kenny6666 [7]2 years ago

4 0

Answer:

√5

Step-by-step explanation:

Given a + 1/a = 3, find its square:

a² + 2a*1/a + 1/a² = 9
a² + 1/a² = 9 - 2 = 7

Now find the square of (a - 1/a):

a² - 2a*1/a + 1/a² =
a² + 1/a² - 2

Substitute the value from the first square:

7 - 2 = 5

Since (a - 1/a)² = 5, its square root is:

a - 1/a = √5

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Which of the following represents the zeros of f(x) = 2x3 − 5x2 − 28x + 15?

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$Factor: 2x^2-11x+5$

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$=x\left(2x-1\right)-5\left(2x-1\right)$

$2x^3-5x^2-28x+15=\left(x+3\right)\left(x-5\right)\left(2x-1\right)$

$\left(x+3\right)\left(x-5\right)\left(2x-1\right)=0$

$\mathrm{Using\:the\:Zero\:Factor\:Principle:}$

thus zeros of f(x) is

$x=-3,\:x=5,\:x=\frac{1}{2}$

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If a+1/a=3 then find the value of a-1/a​

If a+1/a=3 then find the value of a-1/a