What does the presence of the peat and soil layer in the glacial till tell you?

Let f(x) = x4- 8x2 . find the relativeextrema of this function using the second derivative test.

What color would an object that reflects green and blue light appear to be in white light? a. blue b. cyan c. magenta d. black

A150 w lamp emits light of wavelength 590 nm uniformly in all directions. what is the photon flux (photons per unit area per unit time) on a small screen at a distance 2.3 m from the lamp? assume the photons are uniformly distributed over the surface of a sphere of radius 2.3 m.