Science (English Medium) Class 12 - CBSE Question Bank Solutions

Prove that : `2sin^-1 (3/5) -tan^-1 (17/31) = pi/4.`

Let  `vec("a") = hat"i" + 2hat"j" - 3hat"k"` and `vec("b") = 3hat"i" -"j" +2hat("k")` be two vectors. Show that the vectors `(vec("a")+vec("b"))` and `(vec("a")-vec("b"))`are perpendicular to each other.

Prove that :

`cos^-1 (12/13)  + sin^-1(3/5) = sin^-1(56/65)`

The function f(x) = `{{:(sinx/x + cosx",",  "if" x ≠ 0),("k"",",  "if" x = 0):}` is continuous at x = 0, then the value of k is ______.

The derivative of sin x w.r.t. cos x is ______.

If f(x) = |cosx|, then `"f'"(pi/4)` = ______.

If f(x) = |cosx – sinx| , then `"f'"(pi/4)` = ______.

Integrate `((2"a")/sqrt(x) - "b"/x^2 + 3"c"root(3)(x^2))` w.r.t. x

Evaluate `int (3"a"x)/("b"^2 + "c"^2x^2) "d"x`

Evaluate `int sqrt((1 + x)/(1 - x)) "d"x`, x ≠1

Find `int x^2/(x^4 + 3x^2 + 2) "d"x`

Evaluate `int "dx"/sqrt((x - alpha)(beta - x)), beta > alpha`

Find `int sqrt(10 - 4x + 4x^2)  "d"x`

Evaluate `int (x^2"d"x)/(x^4 + x^2 - 2)`

Evaluate `int (x^2 + x)/(x^4 - 9) "d"x`

If `int (3"e"^x - 5"e"^-x)/(4"e"6x + 5"e"^-x)"d"x` = ax + b log |4e^x + 5e –x| + C, then ______.

If x = `int_0^y "dt"/sqrt(1 + 9"t"^2)` and `("d"^2y)/("d"x^2)` = ay, then a equal to ______.

Verify the following:

`int (x - 1)/(2x + 3) "d"x = x - log |(2x + 3)^2| + "C"`

Verify the following:

`int (2x + 3)/(x^2 + 3x) "d"x = log|x^2 + 3x| + "C"`

Evaluate the following:

`int ((x^2 + 2))/(x + 1) "d"x`