(Q6)Find the values for tan 90° ,cosec 90° ,sec 90° and cot 90° .

CAB

From the adjacent figure, the trigonometric ratios of ∠A,gets larger and larger in △ABC till it becomes 90°

As ∠A get larger and larger, ∠c gets smaller and smaller. Therefore, the length of the side AB goes on decreasing. The point A gets closer to point B. Finally when ∠A is very close to 90°,∠c becomes very close to 0° and the side AC almost coincides with side BC.

AB = 0 and BC = AC

Now, tan 90° =
Opposite side
Adjacent side
 =
BC
 =
BC
 =

∝ 0
cosec 90° =
Hypotenuse
Opposite side
 =
AC
 =
AC
 =
sec 90° =
Hypotenuse
Adjacent side
 =
AC
 =
AC
 =

∝ 0
cot 90° =
Adjacent side
Opposite side
 =
BC
 =
BC
 =