Question

If f(x) = (x – a1)2 +(x – a2)2 + ……….(x – an)2 find x where f(x) is minimum.



∞



a1+a2+........Anna1+a2+........Ann



a1−a2−........−anna1−a2−........−ann



– ∞



if the quadratic equations 3x2 + ax + 1 = 0 and 2x2 + bx + 1 = 0 have a common root then the value of 5ab – 2a2 – 3b2, where a, b ∈ r, is equal to



zero



1



–1



none of these



the set of values of a for which 1 lies between the roots of equation x2 – ax – a + 3 = 0 is



(–∞ , –6)



(–∞ , –6]



(–∞ , –6) ∪ (2, ∞ )



(2, ∞ )



if α , β are the roots of the equation ax2 + bx + c = 0, then the quadratic equation whose roots are α1+αα1+α and β1+ββ1+β is



ax2 – bx(1 – x) + c(1 – x)2 = 0



ax2 – bx (x – 1) + c (x – 1)2 = 0



ax2 + bx(1 – x) + c(1 – x)2 = 0



ax2 + bx (x + 1) + c (1 + x)2 = 0



if log72=m,log72=m,then log4928log4928is equal to



2(1+2m)2(1+2m)



1+2m21+2m2



21+2m21+2m



1+m1+m



if loge(a+b2)=12(logea+logeb)loge(a+b2)=12(logea+logeb), then relation between a and b will be[upseat 2000]



a=ba=b%0

Answer 1

cow is tied to a pole at the centre of a grazing plot .when the Rope is taut (tight), the cow can describe the circle of circumference 132 m.calculate the length of the Rope and the area of the land on which it can