Phil-- HELP NEEDED ASAP

Verify the Identity: sin(x+π)/cos(x+3π/2) =tan^2x-sec^2x I've done: sinxcosπ+cosxsinπ / cosxcos(3π/2) - sinxsin(3π/2) sinx(-1) + cosx(0) / cosx(0)- sinx(-1) -sinx/sinx What do I do from here? Or what did I do wrong?

Find the exact value of the expression without a calculator: sin(3π/4+5π/6) I've done: sin(9π/12 + 10π/12) =sin(19π/12) What do I do now? Im confused if that would just be the answer or what? Wouldnt the answer be numerical?

A parallel plate capacitor has a capacitance of 9.1 μF when filled with a dielectric. The area of each plate is 2.0 m2 and the separation between the plates is 1.5 x 10-5 m. What is the dielectric constant of the dielectric?

Capacitor A and capacitor B both have the same voltage across their plates. However, the energy of capacitor A can melt m kilograms of ice at 0 °C, while the energy of capacitor B can boil away the same amount of water at 100 °C. The capacitance of capaci...

An empty capacitor has a capacitance of 1.86 μF and is connected to a 12-V battery. A dielectric material (κ = 4.5) is inserted between the plates of this capacitor. What is the magnitude of the surface charge on the dielectric that is adjacent to either...

thank you!

Thank you!

What is the Capacitance of capicitor b?