Two pulses travelling on the same string are described by the equation $y_1=\frac{5}{(3x-4t{)}^2+2}$ and $y_2=\frac{-5}{(3x+4t-6{)}^2+2}$ with respect to these string waves. Mark the correct statements.

At $t=\frac{4}{3}s$ the two waves cancel each other everywhere 

At all the points, two waves always cancel.

At $\mathrm{x}=1\mathrm{m}$ the two waves always cancel each other

At $t=\frac{3}{4}s$ the two waves cancel each other everywhere