Assuming you mean -90 degrees, not radians:
tan (-90) = [sin(-90)]/[cos(-90)] = (-1) / 0
You cannot divide by zero. tan (-90) is undefined/does not exist.
If B is 90 degrees, Tan A is BC / AB. But I don't know what you mean by Tan A by 2.
Tan(90) is infinitely large. Hence it is deemed not solved. Have a look at the graph of the Tan function. Youwill see it passes through '0' at an angle of 45 degrees. At 45 degrees , the graph line is steeper. At 89 degrees it is almost a vertical line. Hence a 90 degrees it is a vertical line and goes off the scale. Hence Tan(90) is unsresolved. Tan(0) = 0 Tan (45) = 1 Tan(60) = 1.7320... Tan(75) = 3.7320... Tan(85) = 11.430... Tan(89) = 57.289.... Tan(89.9) = 572.957... Tan(89.999....) = 57295779.51 Notice how the Tan values becomes larger and larger with increasing angle. Hence Tan(90) = unresolved; off the vertical scale.
Tan(90) is an infinitely large number, and unresolved.
It is not defined.
To find the value of (\tan(15^\circ) \tan(195^\circ)), we can use the identity (\tan(195^\circ) = \tan(15^\circ + 180^\circ) = \tan(15^\circ)). Thus, (\tan(195^\circ) = \tan(15^\circ)). Consequently, (\tan(15^\circ) \tan(195^\circ) = \tan(15^\circ) \tan(15^\circ) = \tan^2(15^\circ)). The exact value of (\tan^2(15^\circ)) can be computed, but it is important to note that it will yield a positive value.
The value of tan A is not clear from the question.However, sin A = sqrt[tan^2 A /(tan^2 A + 1)]
tan(135) = -tan(180-135) = -tan(45) = -1
The principal range of arc tan is an angle in the open interval (-pi/2, pi/2) radians = (-90, 90) degrees.
tan(22.5)=0.414213562
On the unit circle at 90 degrees the 90 degrees in radians is pi/2 and the coordinates for this are: (0,1). The tan function = sin/cos. In the coordinate system x is cos and y is sin. Therefore (0,1) ; cos=0, & sin=1 . Tan=sin/cos so tan of 90 degrees = 1/0. The answer of tan(90) = undefined. There can not be a 0 in the denominator, because you can't devide by something with no quantity. Something with no quantity is 0. Or, on a limits point of view, it would be infinity.
5400
tan0.15