Posts

Showing posts from May, 2013

Solution of question asked by Mr. Ravi Raj Anand - III

Image
Ques: If   then find the value of   ? Graphical Approach: Let us take 'x' in place of  . Graph of  : it is a periodic function, because cot x is periodic and the period is  . So, we have to draw graph for a period   and repeat for entire values of x. Range of   =  so Range of   =  We know that,   , if  since,  , if   or  so, first draw the line   for   and repeat it for entire x. Similarly, draw the graph of   , if   or  and range of  Draw both the graph together to get the difference, Clearly, in interval   the difference is pi, both the graph are represented by lines in this interval which are parallel. Thus, throughout the interval difference will be the same i.e. pi . i.e.    ( since graph of arccotx is above arctanx, therefore in difference put minus s...

solution of question asked by Mr. Ravi Raj Anand -II

Image
Ques: If   then find the value of x, where [.] denotes the greatest integer function. Sol. Since [.] gives the integer value and both the functions i.e.   and    are always greater than '0'. Therefore, sum of    when BOTH are '0'. STEPS : We separately find the interval of x for both the expression i.e.   and     for which they are zero and then take the INTERSECTION of both the intervals. 1. First consider   , see the graph, Clearly, from the graph,  , if   or    ..................... (1) 2. Consider,  understand the below graph, Clearly from the graph,  , if   or   .................... (2) Now, we have to take the intersection of (1) and (2) i.e. to find the values of x for which both   and  are '0'. so,  But to take intersection of these two intervals we have to find where these numbers viz. cos1,...