If ` sin C =( 15)/(17) , `then find ` cos C ,`

If .^(n+1)C_n=17 , then find n.

If ""^15C_(3r)=""^(15)C_(r+3) , then find r .

If (sin A)/3 = (sin B)/3 = (sin C)/4 , then prove that, cos C=1/9 .

If theta is a positive acute angle and cos theta=(15)/(17) , find the values of the other trigonometric ratios.

In a triangle ABC, if a, b, c are in A.P. and (b)/(c) sin 2C + (c)/(b) sin 2B + (b)/(a) sin 2A + (a)/(b) sin 2B = 2 , then find the value of sin B

If A = { 3, 5, 7, 9, 11 }, B = {7, 9, 11, 13}, C = {11, 13, 15} and D = {15, 17} , find A ∩ C ∩ D

If (1+x)^(15)=C_0+C_1x+C_2x^2++C_(15)x^(15), then find the sum of C_2+2C_3+3C_4++14 C_(15)dot

In triangle XYZ, angle Y is right angle , XZ =17cm and YZ =15 cm then find (1) sin X (ii) cos Z (iii) tan X

In a right angle triangle ABC, right angle is at B ,If tan A=sqrt(3) , then find the value of (i) sin A cos C+ cos A sin C " "(ii) cos A cos C -sin A sin C

If A = { 3, 5, 7, 9, 11 }, B = {7, 9, 11, 13}, C = {11, 13, 15} and D = {15, 17} , find A ∩ (B ∪ C)