Value of cos 0° . cos 30° . cos 45° . cos 60° . cos 90° is ______

The pair of lines represented by the equations 2x + y + 3 = 0 and 4x + ky + 6 = 0 will be parallel if value of k is _________

OR

If the quadratic equation x² – 2x + k = 0 has equal roots, then value of k is ______

The value of sin 60° cos 30° + sin 30° cos 60° is _______

The sides of two similar triangles are in the ratio 2: 3, then the areas of these triangles are in the ratio _______

Δ PQR is right angled isosceles triangle, right angled at R. Find the value of sin P.

OR

If 15 cot A = 8, then find the value of cosec A.