Answer:

Step-by-step explanation:
![1-2\sin^2x=\sin x\\\\\text{substitute}\ t=\sin x,\ t\in[-1,\ 1]\\\\1-2t^2=t\qquad\text{subtract t from both sides}\\\\-2t^2-t+1=0\qquad\text{change the signs}\\\\2t^2+t-1=0\\\\2t^2+2t-t-1=0\\\\2t(t+1)-1(t+1)=0\\\\(t+1)(2t-1)=0\iff t+1=0\ \vee\ 2t-1=0\\\\t+1=0\qquad\text{subtract 1 from both sides}\\\boxed{t=-1}\\\\2t-1=0\qquad\text{add 1 to both sides}\\2t=1\qquad\text{divide both sides by 2}\\\boxed{t=\dfrac{1}{2}}](https://tex.z-dn.net/?f=1-2%5Csin%5E2x%3D%5Csin%20x%5C%5C%5C%5C%5Ctext%7Bsubstitute%7D%5C%20t%3D%5Csin%20x%2C%5C%20t%5Cin%5B-1%2C%5C%201%5D%5C%5C%5C%5C1-2t%5E2%3Dt%5Cqquad%5Ctext%7Bsubtract%20t%20from%20both%20sides%7D%5C%5C%5C%5C-2t%5E2-t%2B1%3D0%5Cqquad%5Ctext%7Bchange%20the%20signs%7D%5C%5C%5C%5C2t%5E2%2Bt-1%3D0%5C%5C%5C%5C2t%5E2%2B2t-t-1%3D0%5C%5C%5C%5C2t%28t%2B1%29-1%28t%2B1%29%3D0%5C%5C%5C%5C%28t%2B1%29%282t-1%29%3D0%5Ciff%20t%2B1%3D0%5C%20%5Cvee%5C%202t-1%3D0%5C%5C%5C%5Ct%2B1%3D0%5Cqquad%5Ctext%7Bsubtract%201%20from%20both%20sides%7D%5C%5C%5Cboxed%7Bt%3D-1%7D%5C%5C%5C%5C2t-1%3D0%5Cqquad%5Ctext%7Badd%201%20to%20both%20sides%7D%5C%5C2t%3D1%5Cqquad%5Ctext%7Bdivide%20both%20sides%20by%202%7D%5C%5C%5Cboxed%7Bt%3D%5Cdfrac%7B1%7D%7B2%7D%7D)


Set up the data:
3,3,3,3,3,6.5,6.5
15+13=28
28/7=4
He runs an average of 4 miles a day
Hello,
Let's assume n,n+1,n+2,n+3,n+4 the 5 numbers
n+(n+1)+...+(n+4)=5n+10=265
5n=265-10
5n=255
n=51
The 5th number is 51+4=55
Answer:
see explanation
Step-by-step explanation:
(a)
Note the squared value in column 3 which is the square of 1 more than the row number, that is
row 2 → (2 + 1)² →3²
row 3 → (3 + 1)² → 4²
Find the square root of 676 = 26 → (25 + 1)² = 26²
Hence the row number is 25
(b)
The pattern in column 1 is [ row number × (row number + 2 ) + 1 ]
row number is n then n(n + 2) + 1 = n² + 2n + 1
Answer:
Q6. D
Q8. A
Step-by-step explanation:
Q6. In 40 trials, he flipped '2 heads and 1 tail' 16 times.
For 2 heads, probability= 16/40= 4/10
For 120 trials, number of times= 4/10 × 120= 48
Q8.

Answer is A because the inequality shows that x is equal or greater than 8 so the dot at 8 has to be coloured.
Note that we do not change the inequality sign unless we are dividing the whole thing by -1.