FUNCTION & GRAPH |
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| Introduction
Functions: Sketch of curve y = sec(sec-1x): Domain R - (-1, 1) & range y = x y R - (-1, 1)y = sec(sec-1x) = x, only when x (- , -1) (1, ) ![]() Sketch of y = cot(cot-1x): Domain R - (-1, 1) & range y = x y = RWe should sketch y = cot(cot-1x) = x R ![]() Sketch of y = sin-1 :Domain [-1, 1] R& range y ![]() b/c y = sin-1 y ![]() Dumb Question: How domain is [-1, 1] R ?Ans: i.e. 2|x| 1 + x2 |x|2 - 2|x| + 1 0 (|x| - 1)2 0 x R Let x = tan y = sin-1(sin2 ) = This curve has sharp edge at x = ± 1 So, not differentiable at x = ± 1 Dumb Question: How does y = - 2 for 2 > Ans: Since our y . So, if 2 > to make it we substract it from - 2 because sin( - 2 ) = sin2![]() Sketch of y = cos-1 For domain 1 |1 - x2| 1 + x2 Which is true for all n; as 1 + x2 > 1 - x2 x R domain [-1, 1] For range y =cos-1 y (0, )Let x = tan y = cos-1 = cos-1(cos2 ) ![]() Dumb Question: How cos-1(cos2 ) = - 2 tan-1x when x < 0 or < 0 Ans: Range of y [0, ]. So, when < 0 or x < 0Then we have to make it b/w [0, ] So, cos-1(cos2 ) = - 2 when < 0 because
This curve has sharp edge at x = 0. So, not differentiable at x = 0. Sketch of y = tan-1 ![]() For domain R except 1 - x2 = 0 i.e. x ± 1 or x R - {1, -1} domain R ![]() Range y = tan-1 ![]() as y = tan-1 y Let x = tan y = tan-1 = tan-1(tan2 ) = ![]() ![]() Dumb Question: Why y = tan-1(tan2 ) = - + 2 tan-1x, for > ? Ans: Range of y & when > So, 2 > .To make it within range we substract So, it comes under range. Because of tan(- + 2 ) = tan2 , this can be done. This curve is neither continous nor differentiable at x = {-1, 1} Sketch of curve y = tan-1 ![]() For domain, y = tan-1 x r except 1 - 3x2 = 0 x ± x R - {± } domain R For range y = tan-1 y Let x = tan y = tan-1 = tan-1(tan3 ) = ![]() Dumb Question: Why tan-1(tan3 ) = + 3 if < - ? Ans: Range of tan-1(tan3 ) is but if < - So, 3 < - So, to make it within given range. We add to it.and in IIIrd quadrant. tan( + 3 ) = tan3 So, this is done. This curve is neither cont. nor differentiable at x = ± . Sketch of y = sin-1(3x - 4x3): For domain y = sin-1(3x - 4x3) x [-1, 1] For range y = sin-1(3x - 4x3) y ![]() Let x = sin y = sin-1(sin3 ) = ![]() ![]() This curve has sharp edge at x = ± 1/2 so, not differentiable at x = ± 1/2. |


R - (-1, 1)
y
, -1)
(1, 

:

i.e.
1 + x2
0
- 2
for 2
= cos-1(cos2


± 1 
= tan-1(tan2

?
& when 
x
= tan-1(tan3

? 



