By first differentiating (√(1-x))/(√(1+x)) obtain an expression dy/dx in terms of x. hence show that the gradient of the normal to the curve at point (x, y) is (1+x)(√(1-x^2))

75 tickets have been sold so far.

step-by-step explanation:

in this question it is clearly mentioned that 45 children's tickets have been sold and this number is 60% of the total tickets sold.

now let's assume the total number of tickets sold be x.

then 60% of x = 45

⇒

⇒ x(.6) = 45

by dividing with .6 on both the sides of the equation

⇒ x = 75

therefore 75 tickets have been sold so far.