Write 0.001247 in scientific notation

The vertex of this parabola is at (-2, 5). which of the following could be it’s equation? a. y=3(x+2)^2-5 b. y=3(x-2)^2-5 c. y=3(x+2)^2+5 d. y=3(x-2)^2+5

The decibel level of sound is 50 db greater on a busy street than in a quiet room where the intensity of sound is watt/m2. the level of sound in the quiet room is db, and the intensity of sound in the busy street is watt/m2. use the formula , where is the sound level in decibels, i is the intensity of sound, and is the smallest sound intensity that can be heard by the human ear (roughly equal to watts/m2).

Which is f(5) for the function –2x2 + 2x - 3?