solve this

the question is x2-√x/(√x)-x limit x tending to 1 plz solve this both by dirct derivative and 1st priciple 2)√tanx solve this by 1st principle

10 Answers

1
chakde ·

questn 1 isnt clear regarding wer the root stops...

can u plz insert (brackets)

62
Lokesh Verma ·

question 1 take √x=t

(t4-t)/(t-t2)

=t(t3-1)/(t(1-t))

Now you can take it from here..

1
coolpal ·

ya correct
bt plz help me solve this both directly by derivative method/alhopitals/chain rule

also by 1st principle

62
Lokesh Verma ·

question 1 take √x=t
=t(t3-1)/(t(1-t))

=-(t2+t+1) = -3

what do you mean by direct derivative? (we need to find the limit!!)

62
Lokesh Verma ·

(√tanx+h-√tanx)
h

=

( tanx+h-tanx)

h(√tanx+h+√tanx)

now this is direct from expansion of tan x+h

1
coolpal ·

thanx a ton

plz solve this 2
tan3x-tanx/
cos(x+pie/4)
x tends to pie/4

1
coolpal ·

PLZ REPLY

62
Lokesh Verma ·

tanx(tanx-1)(tanx+1)

=tanx(sinx-cosx)(sinx+cosx)/cos2x

=√2tanx(1/√2sinx-1/√2cosx)(sinx+cosx)/cos2x

=√2tanx(sin(x-pi/4))(sinx+cosx)/cos2x

=-√2tanx(sin(pi/4-x))(sinx+cosx)/cos2x

=-√2tanx(cos(pi/4+x))(sinx+cosx)/cos2x

now the given question we have to divide by cos (pi/4+x)

so the given question becomes

=-√2tanx(sinx+cosx)/cos2x

=-√22/(1/2) = -4

62
Lokesh Verma ·

check for mistakes in the above..

I think it should be right though!

1
coolpal ·

totally correct
thanx

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