Ask a Doubt
Request a call back

Join NOW to get access to exclusive study material for best results

CBSE Class 10 Answered

Page 255 Question 7 The sum of p terms of an AP is q and sum of q terms is p. Then prove that the sum of (p+q) terms is –(p+q)
Asked by miniprasad | 08 Dec, 2018, 10:45: PM
answered-by-expert Expert Answer
Let a be the first term and d be the common difference
 
Sum of p terms = (p/2) [2a +(p-1)d ]= q   or 2a +(p-1)d = 2q/p ...................(1)
Sum of q terms = (q/2)[ 2a + (q-1)d]= p   or 2a +(q-1)d = 2p/q ....................(2)
 
Eqns.(1) and (2) are two linear equations. These equations can be solved to get a and d
 
we get begin mathsize 12px style a space equals space fraction numerator p squared plus q squared minus p minus q plus p q over denominator p q end fraction space space space a n d space space d space equals space minus fraction numerator 2 left parenthesis p plus q right parenthesis over denominator p q end fraction end style............................(3)
 
Sum of (p+q) terms  = begin mathsize 12px style open parentheses fraction numerator p plus q over denominator 2 end fraction close parentheses space open square brackets 2 a space plus space open parentheses p plus q minus 1 close parentheses d close square brackets end style..........................(4)
substitute for a and d using eqn.(3) in eqn.(4) and simplify the algebric expression to get the answere -(p+q)
Answered by Thiyagarajan K | 09 Dec, 2018, 09:13: PM

Application Videos

Concept Videos

Multiple Choice Questions Practice Test
Answered Unanswered My Questions My Answers
CBSE 10 - Maths
PQ is a chord of length 8 cm to a circle of radius 5 cm. The tangents P and Q intersect at a point T. Find the length of the tangent TP.
Asked by yalagondanikhil | 16 Apr, 2024, 12:25: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Maths
if one of the zeroes of quadratic polynomial F(x) = 4x² - 8kx - 9 is equal in magnitude but opposite in sign, find K
Asked by rrajansinghakb199 | 08 Apr, 2024, 05:12: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Maths
express 15.265 in p/q form?
Asked by nagalaxmidurgarao937 | 08 Apr, 2024, 01:42: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Maths
the poles AB and CD of different heights are standing vertically on the ground level from a point P on the line joining the foots of the pole on the level of ground the angle of elevation to the top of the pole are founded to be complementary the of the CD and the distance PD 20√3m and 20m respectively if the BP is 10m then find the length of AB and the distance AC between the tpo of the poles
Asked by mraniruddha03 | 02 Apr, 2024, 06:44: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Maths
from the pair of linear equations in the following problems and find their solution graphically 10 students of class 10 to part in a mathematic quiz if the number of girls is for more than the number of boys find the number of boys and girls who took part in the quiz
Asked by muttenenimalleswarrao | 29 Mar, 2024, 08:32: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Maths
maths
question image
Asked by sonawnerohan01 | 23 Mar, 2024, 12:25: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Maths
The distance of the point (5,-2) from x-axis will be :-
Asked by pathakvaishnavi9139 | 23 Mar, 2024, 10:45: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Maths
income of families locality are given. find the mode of the data (income in rupees)=1-200,201-400,401-600,601-800,801-1000 and number of families are 7,10,16,12,3
question image
Asked by mustafahssn786 | 23 Mar, 2024, 06:25: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Maths
5 tan^2A - 5 sec^2A
Asked by choudharyniki001 | 22 Mar, 2024, 08:49: AM
ANSWERED BY EXPERT ANSWERED BY EXPERT
CBSE 10 - Maths
A blacksmith has a rectangular sheet of iron. He has to make a cylindrical vessel both circular ends are closed. When he minimizes the wastage of the sheet of iron, then what is the ratio of the wastage to the utilised area of sheet?
question image
Asked by jagdishdabang79 | 18 Mar, 2024, 08:40: PM
ANSWERED BY EXPERT ANSWERED BY EXPERT
My Class Videos Tests ₹ Plans Ask a Doubt
Get Latest Study Material for Academic year 24-25 Click here
×