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If x be real, then the minimum value of ...

If x be real, then the minimum value of `x^(2)-8x+17` is

A

`-1`

B

0

C

1

D

2

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The correct Answer is:
To find the minimum value of the quadratic expression \( x^2 - 8x + 17 \), we can follow these steps: ### Step 1: Identify the quadratic expression We start with the expression: \[ f(x) = x^2 - 8x + 17 \] ### Step 2: Complete the square To find the minimum value, we can complete the square for the quadratic expression. The general form of completing the square is: \[ ax^2 + bx + c = a\left(x + \frac{b}{2a}\right)^2 + k \] where \( k \) is a constant. For our expression: - \( a = 1 \) - \( b = -8 \) - \( c = 17 \) We take half of \( b \) (which is -8), square it, and adjust the expression: \[ f(x) = x^2 - 8x + 17 = (x^2 - 8x + 16) + 1 = (x - 4)^2 + 1 \] ### Step 3: Analyze the completed square The expression \( (x - 4)^2 \) is always non-negative (i.e., \( \geq 0 \)) since it is a square term. The minimum value of \( (x - 4)^2 \) occurs when \( x - 4 = 0 \) or \( x = 4 \). ### Step 4: Find the minimum value Substituting \( x = 4 \) back into the completed square expression: \[ f(4) = (4 - 4)^2 + 1 = 0 + 1 = 1 \] Thus, the minimum value of the expression \( x^2 - 8x + 17 \) is: \[ \boxed{1} \]
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DISHA PUBLICATION-COMPLEX NUMBERS AND QUADRATIC EQUATIONS -Exercise -2 : Concept Applicator
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  3. The value of lambda for which the sum of squares of roots of the equat...

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  4. The set of all real numbers x for which x^2-|x+2| +x gt 0 is

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  5. If alpha,beta are the roots of the equation ax^2+ bx +c =0, then alp...

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  6. If log(1/2) ((x^2+6x+9)/(2(x+1)) )< - log2(x+1) then complete set of v...

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  7. Solve: x^(2) + 2 = 0

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  8. If a<b<c<d , then the roots of the equation (x-a)(x-c)+2(x-b)(x-d)=0 a...

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  9. If the cube roots of unity are 1,w w^2,then the roots of the equation ...

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  10. Find t values of the parameter a such that the rots alpha,beta of the ...

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  11. If w is a complex cube root of unity, then the value of w^(99)+w^(100)...

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  12. If alpha and beta are the roots of the equation x^2+px+(3p)/4=0 such t...

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  13. The quadratic equations x^2""6x""+""a""=""0""a n d""x^2""c x""+""6"...

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  14. If x be real, then the minimum value of x^(2)-8x+17 is

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  15. If one root of the equations ax^(2)+bx+c=0 and bx^(2)+cx+a=0, (a, b, c...

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  16. State true or false for the following. The inequality |z - 4| lt ...

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  17. If 1,alpha1,alpha2,alpha3,alpha4 be the roots x^5-1=0, then value of [...

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  18. If z be any complex number (z!=0) then arg((z-i)/(z+i))=pi/2represen...

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  19. Let z1 and z2 be theroots of the equation z^2+az+b=0 z being compex. F...

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  20. Consider f(x)=x^2-3x+a+1/a, a in R-{0}, such that f(3) gt 0 and f(2) l...

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