Question

If the angle of elevation of the cloud from a point h metres above the lake is alpha and the angle of depression of its reflection in the lake is beta prove that the height of the cloud is h(tan beta + tan alpha)/tan beta-tan alpha

Answer 1

after whats shown in the image ...u have to do the following steps
x+h=2tanhalpha/tan beta +h
2htanalpha +h (tanbeta-tanalpha)/tanbeta -tanalpha
expand bracket then take common that is take h as common
h (2tanalpha +tanbeta -tanalpha)/tanbeta -tanalpha
=h (tanalpha+tanbeta)/tanbeta-tanalpha