We may have a velocity requirement. We can differantiate the

Freudeinstein equation with respect to time and get an equation containing velocities.

$-k_1*{}_4^{}*sin{}_4+k_2{}_2^{}sin{}_2=-({}_4^{}-{}_2^{})sin({}_4-{}_2)$

Two of our requirements can be positions and one requirement

can be a velocity at one of the given positions

A characteristic problem can be as follows:

A $4-$bor mechanism is required to provide the following two positions

Position $1\frac{{}_2}{0}\frac{{}_4}{90}$

Position $29070$

at position $(2),$ the output link is required to have

a $Cw$ velocity of $1$rad$/$s while the input link velocity is $2$rad$/$s ccw EQUATIONS IN PHOTO

Solve these equations for $k_1,k_2,k_3$ Then take $a_1=10cm$

and find $a_2,a_3,a_4$