Question

4 B) Solve the following subquestions. 1) Decide whether the equation r2 - 2x + 5 = x2 is a quadratic equation or not. 2) What is the sum of the first 20 natural numbers ?​

Answer 1

Answer:

1) Yes

2) 210

Step-by-step explanation:

1) r²-2x+5=x²

x²-r²+2x-5=0

=> maximum power of x is 2 , so it is a quadratic equation

2) we need to find 1+2+3+4+....+20

it is a Arithmetic Progression (AP)

sum of an AP = n/2(2a+(n-1)d)

here , a=1. (first term)

d=1. (common difference)

n=20. (total number of terms)

=> sum = 20/2(2×1+(20-1)×1)

sum = 210