ANSWER
C) 1, 3, 6, 10, 15, 21, 28, 36, 45
EXPLANATION
The recursive formula is,
when n is a natural number greater than 1.
When n=2,
when n=3,
when t=4,
When t=5,
when t=6,.
when t=7
When t=8,
When t=9,
Hence the first nine triangular number are
Answer:
+ 1
Step-by-step explanation:
Given
x² + 2x = 9
To complete the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(1)x + 1² = 9 + 1²
(x + 1)² = 10
henc X = 30°
here is the proof
when X=30° then
sin2x = sin2×30
=sin 60°
= √3/2
or else,
putting value of X = 30° then
sin2x= 2sinxcosx
= 2×sin30°×cos30°
=2×1/2×√3/2
= 2√3/4
hence proved sin2x= √3/2.