Toán 9

P

pinkylun

ta có:

$\cos a =0,6$

$=>a=\cos^{-1} (0,6)=53^o 7'48,37''$

$=>\cot a=\dfrac{1}{\tan a}=\dfrac{3}{4}$
 
H

hien_vuthithanh

1.

$sin^2a+cos^2a=1 \rightarrow sin^2a=0,64$

Có : $\dfrac{1}{sin^2a}-1=cot^2a \rightarrow cot^2a=\dfrac{9}{16}$

$\rightarrow |cota|=\dfrac{3}{4}$
 
You must log in or register to reply here.
Top Bottom