Please help me i am in 11th grade. These were the questions asked to me in a test and after the test was over the teacher asked to sumbmit the complete set of solutions for the test in four days time. There were total thirty questions I was able to do seventeen. I need help plz or i will be mincemeat...(adsbygoogle = window.adsbygoogle || []).push({});

I need the step-by-step solutions of the following problems and theorums, axioms used if any.

although i have the correct answers...I want the Working.

well.... here goes.....:

1] If the expression mx - 1 + 1/x is non negative for all positive real x, then the minimum value of m must be:

(a) -1/2 (b) 0 (c) 1/4 (d) 1/2

2] If a,b,c are thepth,qth,rth terms of an Harmonic Progression, then

ab(p-q) + bc(q-r) +ca(r-p) equals

(a) 1 (b) -1 (c) 0 (d) None

3] Given p Arithmatic Progressions, each of which consists of n terms. If their 1st terms are 1,2,3,...,p and common differences are 1,3,5,...,(2p-1)

respectively, then the sum of the terms of all the progressions is:

(a) np(np+1)/2 (b) n(p+1)/2 (c) np(n+1) (d)None

4] the straight line y = x + 2 rotates about a point where it cuts the x axis and becomes perpendicular to ax + by + c = 0 then its eqn is

(a) ax + by + 2a =0 (b) ax - by - 2a = 0

(c) bx + ay - 2b =0 (d) ay - bx + 2b = 0

5] Points on the line x + y = 4 that lie at a unit distanance from 4x+3y-10=0 are

(a) (3,1)&(7,11) (b) (-3,7)&(2,2) (c) (-3,7)&(-7,11) (d)none of these

6] two lines are given by (x-2y)2 + c(x-2y) = 0 the value of c such that the distance between them is 3 is

(a) c=0 (b) c=±v3

7] drawn from the origin are two mutually perpendicular lines forming an isoceles triangle together with the st. line 2x+y=a then the area of the triangle is

a) (a^2)/2 b) (a^2)/3 c) (a^2)/5

8] The minimum value of (sin a)^2 + (cos a)^4 is

a) 3/8 b) 1 c) 3/4

9]Value of sin 10° + sin 50° + sin 70° =

a) 1/16 b) 1/8

10] If

cos² A + cos² B + cos² C = 1 then triangle ABC is

a) equilateral triangle b)right triangle c)isoseles triangle

11]in a triangle ABC, tan(A/2), tan(B/2), tan(C/2) are in harmonic progression. then cot(A/2)*cot(C/2) is

a)1 b) 2 c) 3

12] If a lies in the third quadrant, then v4(sin a)^4 + (sin a)^2 + 4 [cos{45°+(a/2)}]^2 equals

a)1 b)2 c)-2

13] If a and ß are two distinct roots of a(tan x)+b(sec x)=c, then tan(a+ß) equals

(a) (a^2 - c^2)/(a^2 + c^2) (b) (a^2 + c^2)/(a^2 - c^2)

(c) 2ac/(a^2 + c^2) (d) 2ac//(a^2 - c^2)

correct answers

1] c

2] c

3] a

4] d

5] a

6] b

7] c

8] c

9] a or b(not sure)

10] b or c(not sure)

11] c

12] b

13] d

List of Symbols used by me

+ alt+3544

a alt+3552

ß alt+3553

p alt+3555

S alt+3556

s alt+3557

F alt+3560

O alt+3562

8 alt+3564

f alt+3565

e alt+3566

n alt+3567

± alt+3569

= alt+3570

= alt+3571

˜ alt+3575

° alt+3576

v alt+3579

n alt+3580

² alt+3581

♂ alt+3595

♀ alt+3596

↕ alt+3602

¶ alt+3604

§ alt+3605

T alt+1257

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Please help me with these problems

**Physics Forums | Science Articles, Homework Help, Discussion**