sin30. cos60 + 1/2 sin45 . cos45=_____
Answers
Answer:
Step-by-step explanation:
n this post our motive is to learn how to fill the table. Once, you learn to fill this table, you would be able to calculate any value in your mind.
How to memorize values of Trigonometric Ratios for 0, 30, 45, 60 and 90 degrees
(i)
Just memorize the values for sin 0
\[^\circ\]
, sin 30
\[^\circ\]
, sin 45
\[^\circ\]
, sin 60
\[^\circ\]
and sin 90
\[^\circ\]
. Even there is no need to try too hard to memorize them. There is an easy way to memorize them.
sin 0
\[^\circ=\sqrt{\frac{0}{4}}=0\]
sin 30
\[^\circ=\sqrt{\frac{1}{4}}=\frac{1}{2}\]
sin 45
\[^\circ=\sqrt{\frac{2}{4}}=\frac{1}{\sqrt{2}}\]
sin 60
\[^\circ=\sqrt{\frac{3}{4}}=\frac{\sqrt{3}}{2}\]
sin 90
\[^\circ=\sqrt{\frac{4}{4}}=1\]
Note down the pattern from sin 0
\[^\circ\]
to sin 90
\[^\circ\]
:
\[\sqrt{\frac{0}{4}},\sqrt{\frac{1}{4}}, \sqrt{\frac{2}{4}}, \sqrt{\frac{3}{4}}, \sqrt{\frac{4}{4}}\]
Hence, we can now fill all sin values in the table.
How to memorize values of Trigonometric Ratios for 0, 30, 45, 60 and 90 degrees
Now, we will fill all the cos values.
All the cos values are filled in opposite order starting from sin 0
\[^\circ\]
to sin 90
\[^\circ\]
. I mean to say that
sin 0
\[^\circ\]
= cos 90
\[^\circ\]
sin 30
\[^\circ\]
= cos 60