Recently Active Mathematics Questions

in any triangle ABC, the value of \sum{} a(b2+c2) cosA is 1) 3 abc 2)3(a2+b2+c2) 3)a2+b2+c2 4)abc answer: 1)3 abc ...

IF K1 = tan 27θ - tan θ and K2 = sin θ/cos 3θ + sin 3θ/cos 9θ + sin 9θ/cos 27θ , then 1. K1 = 2K2 2. K1 = K2 + 4 3. K1 = K2 4. none of these ...

Plz give me all the necessary theorems for solving the chapter Equations, Inequations and expressions. ...

*Image* *Image* *Image* *Image* ...

1 problem from FMO. Given that \sqrt{n}+\sqrt{n+2005} is an integer. Find all integers n for which it is true. ...

Prove that :- \sum_{r=1}^{n}{tan\ r\ \alpha }\ .\ tan\ (r+1)\ \alpha = cot\ \alpha \ . \ tan\ (n+1)\ \alpha\ - n - 1 ...

Show that a4b+1 - a is divisible by 30 ...

find x,y,z 4x2+25y2+9z2-10xy-15yz-6zx=0 and x+y+z=5 ...

(12x-1)(6x-1)(4x-1)(4x-1)(3x-1)=5 find x. ...

In a n sided regular polygon the probability that the two diagnols chosen at random will intersect inside the polygon is .................. i m bit confused abt the prblm....help ...

q1.) f(x).f( 1/x ) = f(x) + f 1/x ) f(3)=28 find f(4). q2.) f(x)= x4+ ax3+bx2+cx+d f(1)=10 , f(2)=20 , f(3)=30 find f(12) + f(-8) plz tell me d general way to solve such functional equations.....i hv found such questions in m ...

solve for x,y x2+y(x+1)=17 and y2+x(y+1)=13 ...

please tell me any good online book for trignometry ...

4^{log_{2}2x}=36 ...

1.If A+B+C = ∏ and A,B,C belongs to (0,∏/2) then prove that secA +secB +secC≥6 2.Prove that sinx.sin2x.sin3x <9/16 3.Prove that in triangle ΔABC cosec A/2 + cosec B/2 +cosec C/2 ≥ 6 4.Prove that in triangle ΔABC ...

If n is an even number and α, β are the root of the equation x2 + ax + b = 0 and β/α is a root of eqn xn + 1 + (x+1)n = 0, and f(x) = x2n + anxn + bn, then which of the following is (are) necessarily true? (a) f(αn) = 0 ...

If α, β are the roots of the equation x2-2x-a2+1 = 0 and γ, δ are the roots of the equation x2-2(a+1)x+a(a-1)=0 such that α, β belongs to (γ,δ) , then find the values of ‘a’. ...

1.prove that sinx.siny.sin(x-y) + siny.sinz.sin(y-z) + sinz.sinx.sin(z-x) + sin(x-y).sin(y-z).sin(z-x) = 0 2.f(α,β)= cos4α/cos2β + sin4α/sin2β then prove that f(α,β) = 1 3.cosA = tanB, cosB = tanC and cosC= tanA then ...

help me out on these ones.... 1)The perimeter of the sector of a cricle is equal to the circumference of the semi circle of the same radius.Find in circular measure the angle subtended at the centre by bounding radii of the s ...

edited........ ...

i cudnt understand a single term, but seems that all r some hi fi concepts.may be many of u know the meaning of these words (lyk our forum experts and johny)........... G. H. Hardy quotes: "The limitations of his knowledge we ...

s=1+2+4+8+16+..........∞ now 2s=2+4+8+16+........∞ so, 2s=s-1 s=-1 but, s=1+2+4+8+16+..........∞ i.e., s=+ve so,-1 is positive ohh my god!! i ll get mad!! :P ...

A fun result. Its more suited for 11th students A sequence is as follows: 1,2,3,4,5,10,20,40,80,160,... i.e. the 1st 5 nos. in AP and then onwards a GP. Prove that every natural number can be obtained as sums of distinct term ...

1)There are seven people in a elevator.The lift stops at 3(unspecified) floors.In each stop or more people get out, but no one boards it.After 3 stops it is found that the elevator is empty.Find the no. of way this can happen ...

The area bounded by the curve x2/3+y2/3=a2/3 Can someone please tell how to solve these kinds of questions in general? Thanks! ...

how is *Image* where *Image* i.e is how is \prod_{k=1}^{n}{\frac{1}{x^2-2x\cos \alpha+1}}=\frac{1}{n}\sum_{k=1}^{n}{\frac{1-x\cos \alpha}{x^2-2x\cos \alpha+1}} ...

help me out on these ones.... 1) The greastest angle of a cyclic quadilateral is three times the least angle and the other two angles are in ratio 4:5.Find the angles in circular measure? 2)If the circumference of circle be d ...

1.The area of the region between x-y+2=0 and curve x= y , y axis is 2.The area inside the parabola 5x2-y=0 but outside the parabola 2x2-y+9=0 What I did for both the sums was first get a quadratic eq. and solve it to get the ...

5x/2 -2x =1 ...

1.Prove that sin2nx + cos2nx ≤ 1 for all x and n≥1 ...