Math Answers

i need help with angles

can help me

Prove that if ABC is triangle and Dis the mid point of BC , then AB^2+AC^2,=2*AD^2+DC^2)

Show that the function
i) 3 u(x, t) = A(x + ct)³ is a solution of the one-dimensional wave equation
ii) u( x, t) =exp(-ut) sin x , is a solution of the one-dimensional heat equation

The electrostatic potential V(x,y) in a rectangular region is governed by the two dimensional
Laplace equation:

∂2 V(x,y)/∂x2 + ∂2 V(x,y)/∂y2 = 0

determine V(x,y) in a rectangular region 0 ≤ x ≤ 20 and 0 ≤ y ≤ 40 for the following
boundary conditions:
V (0, y) =V(20, y) =V(x,0) = 0
and
V (x,40) =110V

Find the radian measures of the angles whose sine is –0.8. Round to the nearest hundredth

–0.93 + 2πn and 2.21 + 2πn

–0.93 + 2πn and 5.36 + 2πn

–0.93 + 2πn and 4.07 + 2πn

–0.93 + 2πn and 5.36 + πn
please explain i dont get it and all the answers i find are like a damn foreign language

Under what condition A.B is not equal to zero and A×B is equal to zero when A and B are two non zero vectors?

Wade has a test score of 77% on his first test and 65% on his second test. What must he score on a third test to have an average of at least 80% overall?

A chain hangs over a nail with 2.0 m on one side and 6.0 m on the other side. If the
force of friction is equal to the weight of 1.0 m of the chain, calculate the time required
for the chain to slide off the nail.

If (-3,4) lies on a curve that is symmetric with respect to the x-axis ,then (3,4) will also lie on the curve.