PLEASEE HELPP ASAP!


Consider a right triangle which is
changing shape in the following
way. The horizontal leg is
increasing at the rate of 11 in/min
and the vertical leg is decreasing
at the rate of 5 in/min. At what rate <
is the hypotenuse changing in
in/min when the horizontal leg is 12
inches and the vertical leg is 9
inches?


Sagot :

Answer:

Step-by-step explanation:

GIVEN:    dx / dt=5 in./min.  and  dy/ dt=−6 in./min.

FIND:    dz/ dt when x=12 in. and y=9 in.

Use the Pythagorean Theorem to get the equation

x2+y2=z2

Now differentiate this equation with repect to time t getting

D{x2+y2}=D{z2}   ⟶

2xdxdt+2ydydt=2zdzdt   ⟶  

(Multiply both sides of the equation by 1/2.)

x dx/ dt+y dy/ dt= z dz/ dt              (DE)

Now let x=12 and y=9 and solve for z using the Pythagorean Theorem.

tex2html_wrap_inline125

122+92=z2   ⟶   z2=225   ⟶   z=15

Plug in all given rates and values to the equation (DE) getting

(12)(5)+(9)(−6)=(15)dz/ dt   ⟶

6=15dzdt   ⟶

dz/ dt=615=25 in/min.

Hope this answer helps you :)

Have a great day

Mark brainliest