Which parts of △DEF can be determined using only the Law of Cosines?

If the speed of an electromagnetic wave is 100,000 cm/s and its wavelength is 100 cm, what is its frequency? a) 100,000 cycles per second (hz) b) 1 × 10-3 cycles per second (hz) c) 10,000,000 cycles per second (hz) d) 1,000 cycles per second (hz)

Ten times the square of a non-zero number is eqaul to ninety times the number

Indicate the formula for the following conditions: p^c(n, r)=