Answer:

Step-by-step explanation:
Given: sin x + cos x
To change the given trigonometry expression in term of sine only.
Trigonometry identity:-
Expression: 
We get rid of cos x from expression and write as sine form.
Expression:

Hence, The final expression is only sine function.
They always try to trick you with this. Remember anything 5 or above would round up, anything 4 and under would round down. So look for the tenth place. that's the 9. The number to the right is 8 which is greater than 5. That means round up. You can't round it to 0.1 because that takes it back down. So you just move it over. The answer is 1.0.
3 4/6 + 1 3/6 = 4 7/6 = 5 1/7
Therefore the answer is B. the sum is between 5 and 6
Hope that helps