If x = a cosθ+ b sinθ and y = b cosθ- a sinθ, then x2 + y2 is equal to
An angle in a semicircle is
A chord of length 16 cm is drawn in a circle of radius 10 cm. The distance of the chord from the centre of the circle is
If pq (p+q) = 1, Then the value of 1/p3q3 -p3-q3 is equal to
If x2 + 1/x2 = 2, then the value of x - 1/x is
The price of an article is decreased by 10%. To restore it to its former value, the new price must be increased by :