WB JEE 2010 | Sequence and Series Question 16 | Mathematics

PREVIOUS NEXT

WB JEE 2010

MCQ (Single Correct Answer)

-0.25

The value of n for which $${{{x^{n + 1}} + {y^{n + 1}}} \over {{x^n} + {y^n}}}$$ is the geometric mean of x and y is

$$n = - {1 \over 2}$$

$$n = {1 \over 2}$$

n = 1

n = $$-$$ 1

WB JEE 2010

MCQ (Single Correct Answer)

-0.25

If angles A, B and C are in A.P., then $${{a + c} \over b}$$ is equal to

$$2\sin \left( {{{A - C} \over 2}} \right)$$

$$2\cos \left( {{{A - C} \over 2}} \right)$$

$$\cos \left( {{{A - C} \over 2}} \right)$$

$$\sin \left( {{{A - C} \over 2}} \right)$$

WB JEE 2010

MCQ (Single Correct Answer)

-0.25

The value of $${2 \over {3!}} + {4 \over {5!}} + {6 \over {7!}} + $$ ............ is

e^1/2

e^$$-$$1

e^1/3

WB JEE 2023

MCQ (Single Correct Answer)

-0.25

If the n terms $${a_1},{a_2},\,......,\,{a_n}$$ are in A.P. with increment r, then the difference between the mean of their squares & the square of their mean is

$${{{r^2}\{ {{(n - 1)}^2} - 1\} } \over {12}}$$

$${{{r^2}} \over {12}}$$

$${{{r^2}({n^2} - 1)} \over {12}}$$

$${{{n^2} - 1} \over {12}}$$

PREVIOUS NEXT

WB JEE Subjects