Which number line represents all of the values of x for the equation x^2 = 16?

Sam used his calculator to find cos 1.75. he wrote down cos 1.75 = .999. how could sam recognize that his answer is incorrect?

Write a polynomial function f of least degree that has rational coefficients, a leading coefficient of 1, and the given zeros. 3, 4+2i, 1+(sqrt)7 the answer is supposed to be: f(x)=x(^5)-13x(^4)+60x(^3)-82x(^2)-144x+360 what am i doing wrong?

Pls brainliest will be awarded if answer is correct