(log x)/ (log 2) +log(x+1)/ (log 3) =2]]>

I really cannot solve this problem . Or we may consider a similar but simpler one of 2- dimensional , perhaps we can get some hint .

From a circle with radius 1 unit , 3 points are picked randomly on its circumference . Find the expected area of the triangle so formed .

]]>I used the cosine rule thus:

Bob

]]>https://www.mathsisfun.com/data/functio … )+abs(x-1)

So just show that the left and right limits are not the same.

Bob

]]>You are correct that the curve tends to zero as x tends to infinity but that doesn't tell us the range. You cannot have the value x=3; it is excluded from the domain, but you can get as close to 3 as you like and as you do the function has larger and larger values. There is no value of 'y' that cannot be attained so the range is ( -∞ , ∞ ) Note y = zero is attained at x = -2

Bob

]]>Good attempt, Monox D. I-Fly! Almost there!

641. If each interior angle of a regular polygon is 135°, find the number of diagonals of the polygon.

]]>Welcome to the forum.

Which ans? I like to encourage posters to work things out for themselves.

Bob

]]>ganesh]]>

30:30 is impossible as the angles don't add up to 90.

45:45 won't work as the opposite and adjacent would be equal in this case.

30:60 won't work as the opposite and adjacent are in the ratio root 3 : 1

Bob

]]>The first method is technically correct.

It is always advisable to use this method.

The second method may give more of less the same value.

This is for the beginners.

]]>they both start marking a paper at 11:00 AM, what is the first time they will finish marking

a paper at same time?

Question 2: Of two kinds of alloy , silver and copper are contained in one in the ratio of 5:1 and in the other in the ratio of 7:2 . What weights of the two alloys should be melted and mixed together so as to make up a 5 lb mass with 80% of silver?

Question 3 :An alloy contains copper and zinc in the ratio of 5:3 and another alloy contains copper and tin in the ratio 8:5 . If equal weights of both alloys are melted together find the weight of tin in the resulting alloy per kg?

Question 4 : The average daily temperature from 9th January to 16th January (both inclusive) was 38.6 degree and that from the 10th to 17th January (inclusive) was 39.2 degree . What was the temperature on 17th January?

]]>Illustration:

LCM of 0.24, 1.2 and 1.92

To find LCM of decimals, we must change the smallest number into whole number by multiplying it by any friendly number i.e. 10, 100, 1000, 10000 etc.

So, we will multiply 0.24 by 100 to make it a whole number (24).

Here, we have multiplied the smallest number by 100 so, the other two numbers will also be multiplied by hundred. Thus, we will get 24, 120 and 192.

Now, we will take LCM of all three numbers. We will get 960.

As, we had multiplied the numbers by 100, so now we will divide the obtained LCM by hundred.

So, we will get 9.6 which is our answer.

*Another Method:*

*Its just like finding the LCM of 24, 120 and 192*.

.

So it would be

.Now, you just move the decimal place back two places.

Required answer : 9.6!

]]>Use ANT's hint to write a general formula for the sum, then prove it works by induction.

Bob

]]>So the roots are

one of them is *ɑ*, the other is *β*. Since the question doesn’t say which is which, you may as well take your pick. Now use De Moivre’s theorem.