Question

pls help me in this problem.
Two sides of a triangle are 5 and 8 units respectively. If the included angle is changing at rate of one radian, at what rate is the third side changing when the included angle is 60 degrees?

Answer 1

remember cosine law ?

Answer 2

yes

Answer 3

i already use it

Answer 4

i got x=7

Answer 5

we have the same drawing

Answer 6

but my answer is x=7

Answer 7

say \(x\) = length of third side