Simplify the expression: 2√  20  −   3√  7  −   2√  5  +   4√  63  .           a. 2√  20  −   3√  7  −   2√  5  +   4√  63    b. 2√  20  −   3√  7  +   4√  63    c. 2√  5  +   9√  7    d. 2√  20  −   4√  7  −   2√  5  plz

explanation:

infrared radiation has wavelength in the range between 700 nm and 1 mm. lets' convert these values into scientific notation, keeping in mind that:

let's start from the lower value, we have:

(we moved the dot two places to the left, so we increased the exponent by 2 units, from -9 to -7)

the higher value is:

so, the range of wavelength of infrared radiation is:

thus, the first answer choice, y = sec x, is the correct one