Question

answer and how to solve

Answer 1

either solve it completely...
but if u want it's ans from competition point of view, then directly put a=.45
question reduce to
$( \sqrt{2} - \frac{1}{ \sqrt{2} })( \sqrt{2 } - \frac{1}{ \sqrt{2} } )(1 + 1) \\ = \frac{1}{ \sqrt{2} } \times \frac{1}{ \sqrt{2} } \times2 \\ = 1$

here is answer...
u can put any angle,,, as all answers are constant,,, and are independent of any types of variable..... so answer is going to be come same for all values of theta

Answer 2

Answer:

Step-by-step explanation:Area of cross section of river= 2 x 45 = 90 m²

so, water flowing into the sea= area of cross section x rate of flowing water

= 90 x 3000

= 270000 m³

there water flowing per minute= 270000 / 60 = 4500 m³