Answer: The value of Theta will be 225° Step-by-step explanation: As per the data given in the question, We know, From sin graph that, Also, we know that, form cos graph, And, since 180 °<225°360° So, the value of Theta will be 225° #SPJ2 I found a question how to find the value of cos 180 , then we all know that its answer is equal to cos 0, which give us 1 as answer. I myself think that the idea of cos 180 is equal to 1 is : cos 1... 10 I humbly ask for help in the following problem. If \begin {equation} A+B+C= 180 \end {equation} Then prove \begin {equation} \ cos A+\ cos B+\ cos C=1+4\sin (A/2)\sin (B/2)\sin (C/2) \end {equation} How would I begin the problem I mean I think $\ cos C $ can be $\ cos ( 180 -A+B)$. But I am unsure what to do next. Hint Rebember that $ \tan ( 180 ^o \pm x ) = \frac {\sin ( 180 ^o \pm x)} {\ cos ( 180 ^o\pm x)}. $ Now draw the trigonometric cycle and observes the measures of sine and cosine.
