18.$\sqrt{(-4)^{2}}$的算术平方根是( )
| A. | ±2 | B. | ±4 | C. | 2 | D. | 4 |
11.在△ABC中,∠C=90°,a=1,b=$\sqrt{2}$,则tanA等于( )
0 288581 288589 288595 288599 288605 288607 288611 288617 288619 288625 288631 288635 288637 288641 288647 288649 288655 288659 288661 288665 288667 288671 288673 288675 288676 288677 288679 288680 288681 288683 288685 288689 288691 288695 288697 288701 288707 288709 288715 288719 288721 288725 288731 288737 288739 288745 288749 288751 288757 288761 288767 288775 366461
| A. | $\sqrt{3}$ | B. | $\sqrt{2}$ | C. | $\frac{\sqrt{3}}{2}$ | D. | $\frac{\sqrt{2}}{2}$ |