A hot air balloon rising vertically is tracked by an observer located 4 miles from the lift-off point. At a certain moment, the angle between the observer's line-of-sight and the horizontal is pi/6, and it is changing at a rate of 0.1 rad/min. How fast is the balloon rising at this moment?

0.533 miles/min

Step-by-step explanation:

Calculate how fast  the balloon is rising at the moment : dy /dt

location from the lift-off point = 4 miles

angle between the observer's line-of-sight and the horizontal ( ∅ )  =

d∅ / dt = 0.1 rad/min

tan ∅ = y / 4

derivate

sec^2 ∅ . d∅ / dt  = 1/4 . dy/dt

= sec^2 . 0.1 = 1/4 . dy/dt

= ( sec^2 0.5238 * 0.1 ) * 4 = dy/dt

dy/dt = 8 / 15  miles/min

answer:  

step-by-step explanation:

here x represents the height of the pole,

and, the height of the shadow of the pole is 12 feet.

also, the angle of elevation from the top of the pole is 40°,

therefore,

by the low of sine,

which is the required equation for finding the value of x,

∠lno ≅ ∠lnm

∠oln ≅ ∠mln

step-by-step explanation:

given   that triangle lno is congruent to triangle lnm.

we have to fill up the blanks in the given question.

according to above order of congruency   kept in mind we can say that

∠lno ≅ ∠lnm

∠oln ≅ ∠mln

ln ≅ ln due to common in both.

hence, by sas congruency,

the side angle side rule   states that if two sides and the included angle of one triangle are congruent to another triangle, then these two triangles are congruent.