Answer:
<h2>cos 60° = 1/2 because the angles are complements</h2>
Step-by-step explanation:
Given sin 30° = 1/2, to check which of the statements is correct we will apply the Pythagoras theorem to a right angled triangle shown in the attachment.
using the SOH CAH TOA trig identity on the right angled triangle, ACD gotten from the equilateral triangle ABC;
From ΔACD, AD is the hypotenuse, DC is the opposite side to the angle 30° and AC is the adjacent.
From the diagram, sin30° = opp/hyp = DC/AD
sin30° = 1/2
Taking consideration of the acute angle 60°, the opposite side to the angle will be AC and the adjacent side will be CD.
According to CAH, cos 60° = adj/hyp = CD/AD
Given CD = 1 and AD = 2
cos60° = 1/2
This shows that sin30° = cos60° = 1/2
Note that ∠CDA and ∠DAC are angles complementary. Complementary angles are angles which have its sum to be 90°
Answer:
which one work more then less then subtract then multiply by 2
Answer:
3900
Step-by-step explanation:
We want the sum from 5 to 195
5, 10, 15, 20,......195
an = 5 + 5(n-1) since we can write this as an arithmetic sequence, adding 5 each time
The sum of the terms of an arithmetic sequence is given by
Sn = n/2 [2a1 + (n - 1)d],
where d is the common difference of 5 and n is the term we want to add to
195/5 = 39 so it is the 39th term
s39 =39/2 [2*5 + (39-1)*5)]
s38 = 19.5[10+38*5]
=19.5*[10+190]
19.5*200
=3900
X^2 -13x +30 = 0
x*x - 15x +2x +15*2 = 0
x(x -15) -2(x -15) = 0
(x -2)(x -15) = 0
x -2 = 0
x =2
x -15 =0
x = 15
2X^3-2x-40=0
Hope this helps