Question

The number of point of intersection of the two curves $y=2\sin xandy={5x}^2+2x+3$ is ?

• A. $\infty$
• B. $0$
• C. $1$
• D. $lessthantwo$

Answer 1

The correct option is A $\infty$

x = { -2 +/- (2^2 - 4 X5X3 )^(1/2) } / 2X5
=> x = {-2 +/- ( 4 - 60)^(1/2) } / 10
=> x = {-2 +/- (imaginary number) } / 10
=> x is an imaginary number
Thus all values of the quadratic are imaginary.
But since the range of y =2sinx only consists of real numbers there can be no points of intersection between these two curves.

Hence it is zero