Question

(1 point) A spotlight on the ground is shining on a wall 20m away. If a woman 2m tall walks from the spotlight toward the building at a speed of 0.8m/s, how fast is the length of her shadow on the building decreasing when she is 8m from the building?

Answer 1

`dy/dt=0.22m/s`

explained by drawing diagram and solved by hand so look at below attach picture.